We’ve been following the Dreem story for a while now, but this is the first time we’ve actually got our hands on the hardware. Having reviewed countless sleep products over the years, with many disappointments along the way, I had an open mind about what to expect from the much hyped headband.
But as it turned out, expectations were surpassed. And that’s why, we’ve awarded Dreem 2 our first ever 5.0 star rating. It’s certainly not cheap, and yes, there are a couple of minor gripes, but we think it sets a benchmark for the consumer sleep-tech industry.
Dreem 2 is the second-generation headband and app designed to help users better understand and improve their sleep. Dreem 2 boasts EEG (brain activity) sleep monitoring, bone conduction audio, a more comfortable headband design, and a vast library of soundscapes, apps, coaching and sleep improvement programs based on the latest sleep science.
Headband Technical Specification:
- Weight: 130g
- Size: One size- S,M,L adjusters are supplied, Head measurement: 520mm to 610mm
- Sensors: 5 electroencephalogram sensors, accelerometer, pulse oximeter.
- Battery life: Up to 12 hours Charging: 2-2.5 hours to 100%
- OS Compatibility: iOS 10 and later, iPhone 5 and later, Android 5.0 and later
- Audio: Bone conduction system, headphone jack 3.5mm
- Interface : Touchpad, Button, LED indicator
- Connectivity : Bluetooth 4.0 Low Energy, Wi-Fi b/g/n 2.4Ghz & 5.0Ghz (no EMFs transmitted during sleep)
- Materials: Hypoallergenic TPU, textiles
- arguably the most accurate consumer sleep tracker on the market
- unprecedented range of applications for improving sleep
- backed by innovative & wide-ranging scientific research programs
- significant comfort improvements over first gen. headband
- zero EMFs (Wifi/Bluetooth) while you are sleeping
- bone-conduction audio works really well, no need for earphones
- raw data access for sleep researchers
Not so Good:
- no web-based portal for viewing your Dreem data
- data analysis/export options limited (raw data access etc available only to researchers)
- no carry case for travelling
Price & Availability
€399 Europe – available now
$TBC USA & Canada – launching very soon as an FDA-registered medical device)
A little background
If you haven’t heard of Dreem yet it’s worth knowing a little of the back story. The company began life as a startup in 2014 (then called Rythm), in the dorm rooms of two French engineering students. Since these humble beginnings, the company has grown to over 120 employees, attracted over $60 million in investment, and now has one of the largest repositories of EEG sleep data in the world.
In 2015, Dreem a prototype version of their headband to 500 beta-testers. This was followed up by the first-generation production headband in 2017, and subsequently this year the company released Dreem 2, featuring several design improvements.
Although from the outset the company may seem like a hardware startup, Dreem is better understood as a ‘platform’ for improving sleep. Similar to Apple, Dreem focusses on tightly integrating hardware and software, to provide an ecosystem of sleep and neuro-technology applications that can be expanded and improved over time.
Research and healthcare
Although Dreem was conceived as a consumer product, the company vision is considerably wider now. This is reflected in Dreem’s multi-faceted and innovative approach to research and development. Partnering with a number of world-leading research facilities, Dreem already has an impressive list of scientific papers, validation tests and clinical trials to its name (see list below) and it scientific advisory board boasts many world-renowned sleep experts including Professors Christof Koch, Russell Foster, Raphael Heinzer and Emmanuel Mignot.
Dreem also offers programs for sleep researchers, pharmaceutical labs and health professionals to use the product for large-scale, remote longitudinal studies, with raw data access and tools for visualizing sleep data.
Even everyday users are able to contribute to sleep research if they want to with Dreem’s ‘Adventurers‘ program whereby you can opt-in to actively participate in on-going research and development, provide feedback and even suggest new features/functionality.
It’s clear that Dreem to their credit, unlike many other sleep technology companies, are putting science and research at the top of the agenda. Here’s a list of some of the studies that have so far been published.
Existing scientific research studies by Dreem
- Performance of a EEG – Debellemaniere et al, 2018
- A deep learning architecture for temporal sleep stage classification – Chambon et al.,2018
- Slow-wave sleep_ From the cell to the clinic – Sleep Medicine Reviews, 2018
- DOSED: a deep learning approach to detect multiple sleep micro-events in EEG signal, Thorey & al, Arxiv, 2019
- Comparison of Dreem to Clinical PSG for Sleep Monitoring in Apnea Patients
- The Dreem Headband as an Alternative to Polysomnography for EEG Signal Acquisition and Sleep Staging – Arnal et al, 2019
Dreem 2: In-depth review
Inside the box, I was surprised to find very few accessories . Just the USB Micro-B charging lead, a selection of power adaptor for international territories and the three interchangeable velcro size adjustment strips (more about these later). No quick startup guide, no manual.
But first impressions of the headband itself, well, they were good. Dreem, looks and feels like a premium product as soon as you get in your hands – hats off to the product design/engineering team. It’s definitely an odd-looking beast, but in a futuristic, Star Trek-ky kind of way. You’re never going to look cool wearing Dreem, that’s for sure, but you’ll be in bed, so it’s only your partner that will ever see you anyway.
All the materials and components have a great feel and finish to them. Whereas some sleep tech products we’ve reviewed over the years have felt cheap and shoddily thrown together, Dreem has that ‘luxury’ kind of feel to it, no doubt partly a result of the collaboration with design guru Yves Behar
Next, let’s take a look at some of the specific improvements that have been made in the new Dreem 2 headband.
If you include the early beta version, Dreem 2 is actually the 3rd product iteration, although on first inspection Dreem 2 doesn’t look that disimilar from the 2016 1st-gen device.
But despite the apparent similarities the improvements made to Dreem 2 are significant. There’s a full breakdown of the differences between Dreem 1 and Dreem 2 on the company website. As CEO Hugo Mercier recently told Tech Radar “we wanted to keep roughly the same design, so it is quite similar, but we remade it from scratch“. Here’s a rundown of some of the most notable upgrades.
Most notably, the materials have been reworked to maximise comfort, adjustability and make the headband even more lightweight. To achieve this, apart from the electronic components, the band is now made mostly of foam and fabric, meaning that apart from the top arch which houses the electronics, the device is now completely bendable which ramps up the comfort stakes considerably compared to the first gen device.
Another subtle but important comfort upgrade are the rear electrodes. In Dreem V1, some users complained that the teeth in the electrodes would become tangled up in their hair at night. Now these electrodes are made of a much softer, super-flexible material which pretty much removes any chance of entanglement.
Dreem have also made the new band adjustable in size. This is achieved with a super elegantly-simple design improvement – a set of 3 interchangeable velcro strips, to suit small, medium and large head sizes. Whereas before the headband was a one size fits all affair, now the sprung elastic in the headband will adjust accordingly to the size of velcro strip you choose.
This might seem like a minor upgrade, but it’s about more than finding the right size fit for the right head. This new fully adjustable Dreem 2 also improves the accuracy of the biosensor data by ensuring the EEG electrodes and pulse oximeter remain in better contact with your scalp.
Another upgrade is in the bone conduction audio system which conducts audio directly from the forehead into the auditory canal, without the need for headphones. After feedback from users, the engineers decided to optimize the audio system to feature only single driver to provide a more immersive audio experience than the previous model which had two bone-conduction drivers
Finally the touch pad has been upgraded to improve more interactivity, and better control features such as volume, starting, pausing sleep programs without the need to get out your phone.
So, those are some of the improvements, but what’s the actual Dreem 2 user experience like…?
In use: Dreem 2 headband
As you’ve no doubt gathered by now, Dreem is an extremely sophisticated piece of tech. Way too sophisticated to provide all the detail here. Plus, I’m not a sleep researcher nor an expert on data science.Fortunately, the company has published a 35-page white paper, breaking down the Dreem experience, the hardware, sensors, algorithms, the R&D process in detail. So if you’re not sated by this review and need some juicier, geekier technical information I encourage you to read the Dreem whitepaper here.
Design and ergonomics
Dreem’s offbeat form factor is the result of taking the principles of clinical sleep-lab technology (aka polysomnography or PSG) and miniaturising it into a wearable that’s compact and comfortable enough to wear at home in bed, night after night.
The headband is covered in soft hypoallergenic TPU fabric and the architectural structure is 3-way affair; two slim fabric/foam sensor bands, one each for the front and back of the head, and a bulkier top arch, which houses the circuit board, touch controls and is the ‘brain’ of the device.
Despite my off-line familiarity with the product, it’s wasn’t immediately obvious to me how to put the thing on. Not being one to read manuals, my instinctive action was to wear it with the top arch facing forward. This obviously was a complete fail, but once I had it on right, it didn’t feel uncomfortable at all.
Dreem 2’s comfort upgrades, ie the substitution of plastic for foam, and the use of softer materials for the back electrodes means that there are no hard surfaces in contact with the front and back of your head. This is important because regardless if you’re predominantly a side sleeper, or back sleeper, all of us shift positions multiple times a night. Previous iterations of Dreem suffered complaints because of these in-bed comfort issues, but thankfully I found no such issues in terms of the headband causing discomfort at night.
Now, the only inflexible, rigid part of the headband is the top arch. But in terms of comfort, this isn’t an issue either, because this part sits near to the top of your skull. So unless you’re performing headstands in your sleep, it’s not going to get in the way, regardless of your sleep position.
Possibly one of the biggest attractions of the Dreem hardware are the built-in EEG (electroencephalography) sensors, which, as well as monitoring and recording the activity of your sleeping brain, provide real-time neuro-feedback data for many app features including the smart alarm, audio playback/volume and more.
Dreem 2 front band showing 4x EEG sensors, bone conduction speaker (centre) and pulse oximeter (far left)
Dreem’s dry EEG electrodes are a proprietary, patented in-house design, made of a top-secret formulation of ‘high-consistency’ silicone, carbon-filled and can incredibly can acquire electrical brain activity signals through the user’s hair.
Although many consumer sleep trackers purport the ability to be able to classify sleep stages using algorithms that take into account metrics such as heart-rate variability or breathing rate, for the best results, you also need to include EEG measurements.
For instance, features such as sleep spindles and K-complexes, prominent markers of stage 2 (light) sleep can only be detected with EEG. In addition, consumer sleep trackers based on just movement and heart-rate data are notoriously sketchy at conflating ‘motionless wake’ ie lying in bed still, with actual sleep.
Although there are undoubtably some decent sleep trackers that just measure movement, or heart rate data, or breathing (for example the Oura Ring which showed ‘promising results’ in a head to head comparison study against PSG), it’s safe to say that without EEG readings, it’s considerably harder for a wearable to provide accurate sleep staging measurements.
All in all there are six EEG sensors built into Dreem, four at the front of the headband (prefrontal position) and two at the back (occipital position). Interestingly if you dig into the company’s white-paper you will find that only 5 of these are used for actual measurement, the 6th being used a a ‘bias’ electrode, which essentially means it’s used as a form of calibration for the others.
Part of the design spec of the headband also ensures that the pressure of the headband is equally distributed across the sensors, to provide optimal contact and maximize comfort.
Perhaps the most unusual design feature of Dreem 2 are the EEG sensors at the back, the rear electrodes. Not only can they they can acquire electrical signals through the user’s hair (don’t ask me how they did that), but they also sport 6-pronged teeth, which makes them look more like some sort of hair clip, rather than a precision engineered brain activity sensor. As we mentioned earlier, these teeth are now made of a very soft, pliable material to avoid the ‘hair tangle-gate’ episodes reported by some users of Dreem V1.
Whilst there’s no way to individual check if all the electrodes are reading correctly, there is a token feature in the app where you can detect ‘live brain activity’. I say token, because it’s just a simple single line graph, which although it doesn’t really give you a breakdown of which sensors are working, it does demonstrate that the EEG sensors are functioning, and that indeed, you’re not brain-dead. But it’s little more that. The live activity function also gives you a readout of your heart-rate via the pulse oximeter.
Alongside the EEG sensors to monitor electrical brain activity, the front band also features a pulse oximeter to measure heart-rate and blood oxygen saturation, another important metric that’s used to help determine your sleep stages.
Lastly, embedded in the top arch is a 3D accelerometer which detects movement whilst you sleep. Although most wearable sleep trackers these days contain an accelerometer, one advantage of placing a movement sensor on the head is that it can give you an indication of your sleeping position and how it changes throughout the night.
In a nice touch, Dreem have incorporated this into the app so you can see at which points of the night you were side-sleeping, back sleeping or I guess, stomach sleeping, if that’s your thing…
In the centre of the front band, in between the biometric sensors is the bone conduction audio system. If you’re not familiar with the technology, the basic gist is that instead of utilising sound vibrations in the air (via speakers or headphones), bone conduction devices transmit audio directly into the ear canal by sending sound vibrations directly to the bones in the skull, in the case of Dreem, via the forehead.
Bone conduction isn’t new technology, it’s been around for hundreds of years, and today it’s applied in many different situations including hearing aids, military communication and scuba diving to name a few. But not many consumer product use it because the audio fidelity isn’t as good as using earphones and it’s much harder thing to do in terms of engineering and design.
However, the obvious advantage of using bone conduction for a sleep product is that you can listen to instructions, music, soundscapes and hear an alarm, without having to wear earplugs or headphones. And although there are many great examples of headphones designed specifically for sleeping, lots of people find it hard to fall asleep with something stuck in their ear canal.
Dreem 2 bone conduction audio system (via Dreem.com)
So what’s the audio experience like with Dreem? Well, as I mentioned, bone-conduction audio, by its nature does not deliver the same dynamic/frequency range that you’d get with normal speakers or headphones. So don’t expect a booming bass-experience like you’d get with a pair of top-line Beats, or the audiophile quality of a pair of reference Grado’s.
But that said, the quality from Dreem is very good. For instance, some of the built-in ambient soundscapes like Campfire and Cafe give you a very immersive audio experience, and you’re easily able to distinguish very small sonic details such as individual voices, and specific birdsong. As a bit of an audio-geek myself I found this quite surprising considering there’s only a single audio driver in the headband, hence no stereo experience. Some psychoacoustic wizardry at play, I guess.
Being unfamiliar to the bone-conduction effect, it took a little getting used to at first, because the sound appears to emanate from ‘inside your head’ rather than any perceived direction. Volume is fully adjustable via the touchpad which I found really useful to make very subtle adjustments as I was drifting off. One thing I found is that the audio experience was better for me when side-sleeping than lying on my back.
One unexpected benefit of bone-conduction audio, is that, if like me, you sometimes like to wear earplugs at night to block out external sounds, then you’re still able to fully participate in all of the Dreem audio content, despite having your ears completely blocked to the external world. So in effect, you’re able to get total noise isolation, and high quality soothing audio at the same time. As far as I’m aware there’s no other sleep technology product I’m aware of that can pull off this neat trick!
Another nice touch is that if you really don’t get on with the bone conduction system, you can bypass it completely with the built-in 3.5mm headphone jack. This works simply and easily, just plug in your existing phones and the audio instantly switches from the bone-conduction driver to your own phones. PI never felt I needed to use this as I was perfectly happy with the built-in system, but it’s a useful feature if you like using your own earphones.
Even though the headband design is minimalistic, Dreem have put extra efforts into ensuring you can use it as a standalone device. This is a great design consideration as one of the principles of sleep hygiene is to try and keep all distractions – like phones, tablets etc – out of the bedroom.
To achieve this, Dreem have incorporated a multi-functional touchpad into the top arch of the headband which allows you to:
- start your night’s sleep program (a long press)
- stop/restart your sleep program (double-tap)
- adjust volume (swipe left or right)
These might seem like minor features, but they actually change the way you think about the device. Without the touchpad, Dreem needs to be umbilically tethered to your phone to operate. And that means having your phone right next to you, enabling Bluetooth, pairing the device, staring at your screen. If you’re trying to solve your sleep issues, then these are things you really want to avoid doing in bed.
With the touchpad however, your phone can be in another room, or even switched off, and you can still use Dreem all night. As long as your headband is charged, simply get into bed, put it on, give a long press on the touch pad and your night will start.
The reason this is able to work without your phone is because the headband features on-board storage, so everything you need during the night, including the audio tracks are already loaded into the headband, negating the need for any tethering, streaming or the headband ‘radio-ing back to base’.
When you initiate a program from the touchpad, it will (obviously) use the last settings you had. Which means that if you want to modify anything to be different than the previous night’s setting – change your alarm time, audio track, etc – in these cases you will need to get your phone out.
EMF’s or rather, the lack of
There’s another upside to having a touchpad and keeping your phone out of your bedroom – zero EMFs (electric and magnetic fields). EMFs are a much debated and controversial topic, and there’s no real scientific consensus, but essentially, the basic argument is that invisible energy waves sent out by our gadgets, phones, microwaves etc, can cause harmful health effects including to your sleep.
Whether or not you believe any of the claims about EMFs, Dreem has got you covered because regardless of whether you’re initiating a night via the touchpad or the app, once your sleep program has started, the headband ceases all contact with the outside world, so there’s no Bluetooth or Wifi radio emissions whatsoever whilst you’re wearing the headband.
The Dreem app
So, onto the software. The Dreem app is available for both Google and iOs devices, specifically iOS 10/iPhone 5 and later, Android 5.0 and later). Once you’ve downloaded the app, you’ll need to fill in your profile information. In an age where we’re increasingly wary of sharing private data, there’s no getting around this step, so you’ll need to enter a few personal details such as your age, gender, and then answer a brief optional survey about your sleep habits.
Once you’ve completed your profile, you can pair the app with your device. Thankfully, this was a breeze, and the app recognised the headband via Bluetooth straight away.
Before you can dive in and unlock all of the app features, you have to complete an initial sleep assessment. This perform several functions. First, it gets you used to sleeping with the unfamiliar sensation of sleeping with a headband on, secondly, it gently introduces you to the features and functionality – without overwhelming you too much, and lastly, it allows the app and machine learning algorithms to get a baseline of your sleep behaviour, in order to make initial recommendations.
There are two assessments you can choose to take, a short and a long option. The short assessment takes 7 nights to fully complete. You’re able to use the audio features, but the app only becomes fully unlocked once you’ve received your first sleep report after 7 days (more about this later).
The longer assessment takes between 14-60 days to complete. This is called a ‘real-user experience’ because once completed you’ll receive a detailed, personalized recommendations, based on your specific sleep needs.
It’s clear from the start that Dreem have put just as much effort, if not more, into making the app user experience as good as it can be. Elegant layouts and subtle behavioural nudges are employed throughout to encourage users to explore the full complexity of the Dreem experience but in a minimalistic, uncluttered way free of information overload
Dreem has chosen cards as their main user interface component. Cards are part of a design language embraced by many big tech companies like Google and Twitter, and they allow designers to communicate and present many complex layers of information whilst retaining simplicity, elegance and ease of use.
Video example of the cards layout -explaining how to read your first night’s report
New cards are presented in a chronological timeline to give you constant feedback on your sleep behaviour. This is your Dreem Coach, providing with highly personalized reports, feedback, suggestions and practicable advice.
Away from the timeline, the cards system is also used to present many other types of information including instructions, sleep reports, sleep metrics and more.
Headband settings and functions
In terms of overall app design, again there’s a refreshing simplicity. There are only 3 tabs/icons permanently available. The first is the home screen -think your Twitter timeline, or Facebook feed – a chronological list in card format of all your personalized Dreem data, including your metrics, daily and weekly reports, coaching advice, and information on any Dreem programs you’re participating in.
The right-hand tab/icon is where you’ll find all of your archive sleep reports, sleep trend data and also the list of longer-term Dreem programs which we cover below.
The middle ‘headband’ tab however is where, unless you’re on a longer-term program, this is where all the real ‘action’ takes place. Here you can choose and select different ‘Dreem Techniques’ aka Sleep, Relax, Nap (more about this later) and activate the Smart Alarm.
Video screenshot of the Dreem app’s Headband functions
This middle tab is also where you’ll find hardware settings for the headphone and check things like battery life, Bluetooth and Wifi connectivity. There’s also a ‘Live EEG’ status page, whereby you can view a simple line graph that represents your live brain activity, plus a readout of your heart-rate.
Dreem seem to have been conservative in their battery life estimates and recommend that users recharge the device every morning when you wake. Although the company recommends charging every night, in practice I found that the device was averaging around 50-58% battery capacity after 1 night’s use. However, the website recommends that you need at least 60% battery to start a sleep session, and indeed the app won’t let you start a sleep session if you’re below 60% capacity.
That said, I think the charging recommendations are correct, because it gets you into a daily routine, allows your nightly sleep data to upload – as well as downloading any firmware updates, and most importantly. As mentioned before you can see the exact battery level in the app, but also you can do a quick check by looking at the power button. Orange means the headband doesn’t have enough battery and needs to be charged, whereas blue means the headband has reached at least 60% charge so you can start a sleep session.
At the moment you’ll have to charge the headband by plugging in a USB lead every morning, but coming very soon is a charging dock which also functions as a stand and, instead of having to plugin the USB lead in, it will utilise the two power connection dots already built in to the top arch of the headband. Again, a really nice design touch which adds to the overall ergonomics and ease of use
Data exporting and analysis
If you’re a biohacker, data-geek or quantified self-er there are a few different options for exporting your Dreem data out of the app.
The simplest way is to sync your Dreem data with your Google Fit account. This can be done easily from within the app, resulting in you being able to see all of your sleep data inside Google Fit alongside your fitness and exercise metrics.
If you want to delve deeper you can use the in-built export function, which will break down your sleep stages into a CSV document for further data mining. This works simply too, but it’s not really that useful looking at a spreadsheet of your sleep stages, unless you have the requisite data juggling skills…. I tried it, it worked, but I had no idea what to do with the data!
Finally, although not available for the general public, if you’re a serious sleep researcher or clinician, you’re able to access and export the raw data files from the headband and using a separate tool, Dreem Viewer, you’re also able to easily visualise the sensor data directly in a similar way that you would interrogate the readings from PSG.
Dreem Viewer Software – a tool available for sleep researchers and clinicians
Dreem Techniques – Sleep, Relaxation, Napping, Smart Alarm
The Dreem ‘Techniques’ are a suite of programs that cover the 24-hour period (as opposed to Dreem’s longer term sleep improvement & sleep restructuring programs). You can access these via the headband tab in the app. The 3 top-level options to choose from are, Sleep, Relax and Nap. Each of these options has further settings to delve into, which have further settings to access.
It sounds like a lot of options to wade through, but the app interface is extremely intuitive and it’s a testament to the app designers is that I rarely had to delve into a help files or search for a support document.
The library of Dreem Techniques is set to expand and grow, and there are too many features to list in detail, but here’s a brief overview:
This is probably the most common of the Dreem Technique you’d end up using most. The Sleep program includes Sleep Onset relaxation programs (see below), the Smart Alarm (see below too!) and results in a full and comprehensive breakdown of your nightly sleep data when you wake in the morning.
In the morning it uploads your data to Dreem’s cloud servers for processing and in a few minutes, your night’s sleep appears in the app in the form of a summary card, in which there are options to explore your Sleep Quality and sleep Metrics. ‘Quality’ is a difficult to fathom at first, graphical representation of various aspects of your night’s sleep. Essentially it’s a proprietary metric combining Sleep Onset, Agitation, Fragmentation, Deep Sleep and Awakenings in the form of a circular graph.
The basic gist is that you want your Quality graph to cover as large an area as possible. You can find out more about the Quality summary here.
Sleep stages, hypnogram and metrics
Fortunately, Dreem’s sleep staging metrics are much easier to comprehend than the Quality graph. Anyone who’s used a sleep tracking app or wearable before will be familiar with a hypnogram display. A hypnogram is the standardized way of representing sleep stages chronologically throughout the night.
I’d safely say that the Dreem app has the neatest implementation of a hypnogram I’ve yet seen in a consumer sleep app. Not only does it break your sleep stages into Wake, Light, Deep and REM sleep, it also lets you clevery ‘zoom’ in, to the nearest minute, show totals for the percentage and duration of different sleep stages, your sleeping position throughout the night, heart rate and breathing. The zoom user-interface has been designed such that even when viewing the hypnogram on your phone it’s really easy to navigate.
Alongside nightly sleep staging data in your timeline, the Dreem Coach also provide personalized advice Cards in the morning to alert you if there was anything notable about your night’s sleep. Examples of this might be to alert you about noticeable changes in your Sleep Onset (time it took to fall asleep), Wake-Up Time (and associated sleep stage), Nocturnal Awakenings, Total Sleep Duration. The Dreem Coach is about providing gentle hints, reminders and occasional nudges towards changing your behaviours.
Reports and Trends
Nightly data is great, but if you want to see how your sleep has changed over time, you can also access an archive of weekly report, plus you can also choose to look at weekly trend data for any the following metrics:
- Sleep onset
- Sleep duration
- Sleep objective
- Deep sleep
- Position changes
Although I didn’t really use the trend data very much, I can really see the value in having easy access to long-term trend data to find out for instance if, over the course of weeks, months or even years, you’re sleeping longer, falling asleep faster or waking up less in the night.
How accurate is Dreem?
So whilst we’re taking about metrics, let’s ask the $64,000 question. Well, sorry but this is going to be a long answer….. because the issues are both complex and contentious.
To elucidate, sleep scientists, researchers and clinicians use a variety of tools to attempt to measure and quantify sleep – ranging from a simple diary, to fMRI scanners costing millions of bucks. But most commonly when people talk about the ‘accuracy’ of consumer sleep wearables they’re referring to their comparative performance against PSG, considered the ‘gold standard’ of sleep measurement tools.
However, hardly any consumer sleep trackers (almost none) have undergone rigorous scientific validation in this regard. ‘Rigourous’ would entail studies that have been through the peer-review process, and have been published in a scientific journal.
More common in the consumer sleep technology world is that companies will perform in-house research and use this data to make claims about their accuracy in their marketing campaigns. This, as you can imagine, makes the term ‘accurate’ very subjective, and somewhat of a moving target. Although Dreem has indeed notched up some journal publications, to my knowledge, there are no peer-reviewed validated studies of Dreem (in comparison to PSG) available as of yet.
All of this taken into account, and in the absence of any agreed validation standards for consumer sleep wearables, I’m gonna stick my neck to say that, based on what I’ve read and researched over my years covering the field, Dreem would seem to be one of the top, if not the top contenders for the title ‘most accurate consumer sleep tracker you can buy in 2019’ .
This isn’t a scientific view, it’s my opinion, and I’m willing to be proved wrong by further independent research. But taking into account; the research that Dreem has so far published, their push to market the headband as a serious research tool, and the availability of raw data access and analysis tools, all these would seem to be indicators that the company is not merely trying to hide behind marketing claims or inaccessible ‘black box’ sleep staging algorithms.
>> Late breaking news, only this month Dreem released the results of a 6-month validation study against PSG. The results look very promising, however, the study has not yet been peer-reviewed or published in a scientific journal. For more information you can read more about the new study here.
If you’re slightly obsessed with sleep-tracking like we are, then check out our 2-part podcast on the subject, where we explore all of the above issues in great detail:
Another Technique is Dreem’s Nap Program. Again this includes the Sleep Onset programs and the Smart Alarm function too, although the implementation is slightly different. I’m a big proponent of naps as a tool for helping to improve and optimize your sleep in general so I was really interested to see the Dreem approach to napping.
As with Sleep, the Nap technique allows you to choose a Sleep Onset program to help you drift off, and then you can set your required nap duration. The unique way that Dreem implements napping however, is that unlike a simple timer that you might set to wake you after 20 minutes, Dreem uses its sleep sensors to determine the amount of time you’re actually asleep, and only once you’ve reached your target nap duration will it then it proceed to wake you up.
The obvious benefit is that if you want to take a nap which actually incorporates ‘real’ sleep (as opposed to just closing your eyes and resting), then Dreem is able to do this for you, so that you know your nap contains a period of objectively measured sleep, rather than your nap being about just ‘dozing’ or ‘winding down’.
The downside with this approach however is if you set a Nap Duration of 20 minutes it will undoubtably be more than 20 minutes before your alarm goes off. For instance, in the screenshot above, you can see that the time interval between starting the nap and waking is actually 28 minutes, ie 8 minutes to fall asleep (at 3:12pm) and then 20 minutes of real sleep (waking me at 3:40pm).
In fact, the first time I used the nap function I thought it was malfunctioning because it was over 40 minutes before my 20 minute nap alarm went off!
Thankfully, there is a get out clasuse, if you’re on a tight schedule. So for instance, if you’re taking a power nap at work, you can choose to set a Maximum Wake-up Time to be sure that your alarm will never go beyond this alloted time.
Finally, Relax enables you to choose one of the same programs featured in Sleep and Nap to help you fall asleep, but with the objective of relaxing, rather than sleep itself. There’s no alarm function in Relax, nor is there any sleep tracking, because the idea is…. not to fall asleep! You do however get some feedback after completing some of the Relax programs, such as the Breathing technique.
Sleep Onset programs
One of the real strengths of the whole Dreem experience is the design and execution of the sleep onset/relaxation programs. There are many interesting facets to how these programs work, so I’ll try to break it down simply.
All of these programs are available in Sleep, Nap and Relax as described above. There are 2 layers; i) a suite of relaxation exercises and ii) a library of ambient soundscapes (NB Ambiance is not available when you choose Relax).
Walkthrough of the Dreem Techniques audio programs
The relaxation exercises are voice-led audio programs using evidence-based techniques from sleep psychology, meditation, mindfulness and sophrology to help relax your body and mind as you drift off. All of the programs are high quality, featuring soothing male or female voices (with American accents), and for each program you get a brief description, and various settings, for example, exercise duration and breathing tempo. Dreem hopes to expand the library in the future, but for now you have:
- Mind Palace – a visualisation technique incorporating sophrology
- Reminiscence – another visualisation technique incorporating memories
- Body Scan – classic mediation/mindfulness technique to relax the body
- Cognition – a word-based technique to prevent mental rumination
- Breathing – a guided-breathing exercise to slow your breaths
- Calming – guided relaxation technique to destress
No doubt, Dreem users will have their favourites. For instance, I didn’t really dig the Cognition or the Breathing techniques, my favourites were Reminiscence and Mind Palace.
It’s worth nothing the bone conduction audio experience. It’s literally like a voice inside your head and takes a few goes to get used to. After a few nights however, I began to really enjoy the intimacy that this created. Point is, it’s a totally different experience to wearing headphones.
Once you’ve chosen one of the vocal relaxation exercises, you then have the option of adding a second layer of sound in the form of an ambient soundscape. You can also skip the vocal tracks and just have Ambiance on its own.
The ambient tracks are high quality with no perceivable looping effects and the names are pretty self-explanatory. There’s quite a selection to choose from:
- White Noise
What’s also really neat is that if you want to combine a vocal track with an ambient track, you get the option to independently control the volume of each track, like having a miniature sound mixing desk built into the headband.
My favourites were Campfire, Pebbles (waves lapping on a beach) and for napping, I liked the Cafe soundscape as it kept me mindful that it was still daytime.
One really important thing to bear in mind about the relaxation programs is that they’re not just passive audio tracks which play until they’re finished. Playback is in fact determined by Dreem’s neuro-feedback system ie it’s responding directly, in real-time to your brain activity.
So for instance, if you choose a 20 minute Mind Palace relaxation exercise, but you fall asleep in 10 minutes, the headband is able to detect this and will gradually fade the audio out so that it’s not playing whilst you’re asleep.
Again, this is a very understated feature, but it’s very smart in its implementation. Normally, if you like to relax to sleep with some soothing audio you will either have to switch it off manually at some point in the night, remove your headphones or have some sort of timer system in place. With Dreem, all of this happens in the background in synchrony with your brain activity.
So called ‘smart alarms’ have been around for a few years now in many sleep tracking devices. The premise is, a smart alarm will only sound when you’re in a stage of light or REM sleep and will avoid trying to wake you if you’re in deep, slow-wave sleep.
The reason is, waking from deep sleep causes sleep inertia, and can make you feel groggy for hours afterwards. Problem is, it’s historically been very hard to do sleep staging with sleep trackers that are based on metrics such as movement and heart-rate.
Dreem’s EEG data however make its smart alarm feature potentially much more accurate than a sleep app or a Fitbit-like device that can’t detect brain activity.
Using the smart alarm is simple and intuitive. After choosing your desired wake-up time, you’ll then be prompted to set a ‘wake-up window’ of 5, 15 or 30 minutes and choose one of 8 different alarm tones (my favourite is ‘Birds’).
Dreem will then calculate the optimal time to wake you within this window, but no longer than your desired wake time.
I don’t generally wake to an alarm, but on the couple of occasions I used it, I woke in the accustomed manner ie not feeling groggy in the slightest.
Believe it or not, even though this is one of the longest reviews we’ve ever done, we’ve still only scratched the surface of describing the Dreem experience.
Perhaps the most exciting and useful aspects of Dreem is the suite of longer-term sleep programs, designed not just to monitor your sleep, but to actively improve it.
The longest of these takes up to 8 weeks to complete, so I didn’t have the opportunity to fully test out all the programs, so I’m only able to give an overview. However, it’s important to note that these sleep programs are at the core of the Dreem mission, to provide not just the most accurate sleep wearable on the market, but to create a ‘sleep reference solution’ a tool that can be used to genuinely improve people’s sleep problems.
Currently there are 4 programs available which vary in terms of difficulty as well as duration:
- Sleep Basics – 2 weeks, Easy
- Rituals – 3 weeks, Easy
- Winning Back Sleep – 2-3 weeks, Average
- Sleep Restructuring – 6-8 weeks, Advanced
Sleep Basics as the name suggests is a simple program designed to be the first step to healthier sleep, with a focus on sleep education and understanding the mechanisms that regulate sleep.
Rituals is all about creating habits to ensure that your pre-bedtime routine is conducive to a good night’s sleep. Hence Dreem monitors your sleep onset (time to fall asleep) and gives you active coaching advice on ways to improve your bedtime rituals
Winning Back Sleep is a program designed for normally good sleepers who just need to improve and change some of their existing behaviours to get back on track and ‘win back’ the sleep you’ve lost due to life circumstances or bad habits.
Sleep Restructuring – Dreem is using the term CBT, however, Sleep Restructuring is modelled on the principles and practices of CBTi (cognitive behavioural therapy for insomnia), which today is recognised as the most effective clinical therapy for insomnia and is rapidly being adopted a first line treatment for insomnia all around the world.
Find out more in the Sleep Junkies Podcast, ‘CBT-I Explained’:
In a nutshell, CBTi bundles a collection of clinically proven sleep therapies/techniques to form a structured, actionable treatment plan that spans a period of between 4-8 weeks. These can be broken down into 4 main areas:
- stimulus control
- sleep restriction
- sleep hygiene
- cognitive therapy
Much has been written about CBTi and these these techniques, so I won’t go into detail here, but if you want to find out more there’s a good summary on the Dreem Blog.
What’s important to note is that there are many types of delivery methods for CBTi. You can complete a course of CBTi by seeing a qualified practitioner in person, or in a group setting, but it’s safe to say that generally there are not enough CBTi professionals to meet demand, so access may be limited depending on where you live.
Another increasingly common option however is what’s often called ‘digital CBTi’, which means using an app or software program to complete the same treatment you’d get in person. Digital CBTi is a great, cost effective delivery method, and there are many choices, including apps like Sleepio that you can access at the push of a button.
Taking the ‘heavy lifting’ out of behavioural sleep therapy
The big differentiating point with Dreem’s CBTi-inspired Sleep Restructuring program is the headband itself. To explain, all CBTi programs require participants to manually log their sleep using either a sleep diary, either in paper, or by logging your data in an app.
Dreem, however doesn’t require you to log anything as the headband does all the ‘heavy lifting’ and instead of relying on your subjective sleep diary timings, Dreem gives you objective data directly from your EEG data, which allows the program to adapt and provide you with precise recommendations based on how you’re progressing through the program.
As Dreem CEO Hugo Mercier explained to us earlier in the year, because of this direct feedback from the headband, testing has shown that the Dreem Sleep Restructuring program has a much higher retention rate than traditional CBT programs because users can instantly see their progress via the app, and they’re not required to do as much work because sleep monitoring is all happening in the background.
All in all, the potential for Dreem’s Sleep Restructuring is huge, and is indeed a key focus for the company’s efforts. CBTi is an extremely effective way to treat insomnia, but the cost, the lack of qualified therapists, and the need to stick with the program for up to 2 months, means that a lot of people who may benefit, don’t. Although Dreem isnt a cheap solution, it falls somewhere between the personalized, guided methods of doing CBTi in person with a therapist, and the scalable, convenient benefits of digital CBTi, but with the added benefits of having ‘objective’ EEG based sleep data and machine learning guidance.
This is the longest review I’ve ever written for a sleep technology product, but even after spending a few weeks with Dreem 2, it still feels like I’ve only scratched the surface.
Dreem has got a lot going on. Detailed sleep monitoring, neuro-feedback, coaching advice, guided sleep/relaxation programs etc. But perhaps its biggest strengths are the longer term Sleep Restructuring applications, modelled on clinically proven CBTi therapy, and designed to treat real patients with real insomnia.
This is very much the target market for the device and no doubt why the headset is launching the headset in the States as an FDA-regulated device. However, even if you’re a biohacker, athlete or anyone who has an interest in the business of ‘quantifying sleep’ – Dreem 2, just as a sleep tracker is unrivalled in the market.
The form factor may be an issue with some. Not everyone is going to want to wear a headband all night. But after a couple of night’s acclimatisation I got used to it and genuinely looked forward to checking my stats in the morning.
Dreem 2 feels like a futuristic product, and I’m encouraged by the amount of research projects the company’s involved in. But it’s not just for ‘techies’ like me. They’ve also worked hard on the design and user experience to make the hardware and software experience as ergonomic as possible.
Highly recommended and genuinely worthy of a 5 star rating.