Digging into the Sleepbuds audio format - it's not complicated, please let us create our own sounds!
I've done some digging into the audio format that the sleepbuds use. The design choices seem strange to me, in that the audio files the buds store for playback are uncompressed digital audio, which uses up more storage space, but less processor power than compressed audio. I suppose storage in the Sleepbuds is cheaper and easier than more processor power, which would impact on battery life.
It also seems strange to me that they are 24-bit audio, which again increases the storage requirements in the devices. For something that's played quietly, 16-bit should have been more than sufficient. Further to this, even though they are uncompressed, high-resolution audio, the sample rate is only 8 kHz (8,192 Hz to be exact, which is a power of 2 but not the more commonly used 8,000 Hz).
As a result of the low sample rate, the audio in the buds is limited to a frequency response of just 4kHz (or 4,000 Hz). Human hearing is ideally 20 Hz (deep, earth shaking bass) all the way up to 20kHz (20,000 Hz) although to be fair, not many people can hear this high.
I'm sure there were valid reasons for chosing an odd format like this - however dropping the resolution from 24-bit to 16-bit would have no audible impact (expecially given the sample rate) and make the audio files 2/3 the size.
I did read elswehere on this forum that one of the reasons given for not letting us make our own audio was that the files were EQ'd especially for the sound profile of the Sleepbuds.
Opening up the audio and comparing it to the full uncompressed waveforms (which are what you listen to for the preview on your phone) shows this to not be the case. The sound is the same (or at least very, very similar for all sounds below 4kHz) from the preview audio (which is an uncompressed 44.1Khz, or 48kHz, 32-bit WAV file)
I appreciate that creating custom sounds could be quite technically involved, and that Bose probably doesn't want to be responsible for supporting people who aren't familiar with a digital audio workflow. For those that have the technical capabilities however, there is so much more we can do with these devices.
We can make sound loops that are longer than 30-40 seconds. We can record environmental sounds that we want to sleep to and find more comforting.
I only need one sound to go to sleep to, I don't need a library of 10 different sounds in the buds. If I could have a single loop of, say, 3-5 minutes rather than 10 sounds each 30 seconds long, then I'd be far less able to detect loop points (and once I've heard a loop point, I can not unhear it - that sound is ruined for me to sleep to). If I could upload my own sounds, I'd go down to the coast for a night and record some of my own seaside night sounds. Gentle wind, surf breaking on the beach, a thunderstorm with some rolling thunder...
Please take this into conisderation - we have all put down a significant amount of money on a luxury item that has so much more capabilities than the current software allows for. I appreciate this is quite a niche market - there aren't many people who can justify spending hundreds of dollars on fancy ear plugs, but for those who have invested in this technology, please let us do more with it.