My biggest concern generally is in-ear comfort. Short of molded customs, every in-ear headphone I've tried causes canal soreness within an hour or two, including the "sound delivery straw" designs with delicate foam or rubber surrounds. Secondarily, it looks like the current model sticks out, causing pressure if one's head is resting on its side.

That said, my ear canal soreness is largely due to canal deformation relating to jaw movement. Perhaps this is not an issue for sleeping. Also, foam earplugs (compared to earphones) are not uncomfortable for me.

What about the need to be woken up by external events which aren't connected to your smart phone? The immediate example I think of is a fire alarm.

If you can deliver on the promise, this would be worth way more than $150 to me. Probably more than $500. I'm a light sleeper and I live in a city - not a great combination.

But I am for now a little skeptical: - I have never used a pair of earbuds or earplugs which are comfortable for more than ~20 minutes. This includes soft foam earbuds and plugs, small-sized musician earplugs (I have tiny ears), and earplugs custom fit by an audiologist. - Even that custom fit pair (which I bought for sleeping) doesn't work for sleeping: I'm a side sleeper, and sleeping on my side applies a little pressure to the ear canal. It's enough that those custom fit earplugs don't fit right when I'm on my side. - Those custom fit earplugs are not even close to mirror images of each other. It's not obvious to me that the same piece of foam can be appropriate for both ears, no matter how deformable it is.

My main point of feedback: focus on comfort - specifically sleeping comfort for people with odd ears and odd sleeping positions - over everything else. I would pay piles of money for earplugs comfortable enough to sleep in with say 10dB reduction, far better that than not-quite-comfy enough smart earplugs with 70dB reduction. Similarly, I would happily sacrifice battery life, aesthetics, cost, smart features, etc. for comfort.

I really like this idea! Combining isolation and masking in a standalone in-ear device is very clever.

Personally I'm less interested in the ability to be interrupted by alerts from a smartphone. When I'm sleeping I want to sleep. When I'm working, I can get vibration alerts from my phone.

Have you considered a 'dumb' version with just pre-recorded masking audio and no wireless features?

Are the batteries going to be replaceable? I worry when the battery ages it won't last through the night. At 10 hours of charge maximum, if the battery loses just 20% of its max capacity, I would run risk of the battery not making it through the night.

Heya! Just backed the project, seems super promising! As a developer have you tested these while coding? I've tried rainymooods which works alright, but I'm wondering now if this wouldn't be more effective (because of the cancelling). Also I may have missed this, but do you have any ideas with regards to motion sensoring or opening the API? It'd be great to buy a motion sensor compatible with Android and hook into the wearables to alert if someone (or in the case of camping something) is nearby.

Your site is down at the moment, so let me ask - as a musician, what do these get me over Etymotic's earplugs? I have a $160 pair of custom-molded plugs with replaceable filters that go from -5 to -20dB attenuation.