I’ve always wanted to buy a noise machine to drown out extraneous sounds and make it easier to sleep or just relax. However, I’ve never found one with the level of quality and features I want at any price. A large full range speaker and strong amplification are key. (One unit boasted that it had a 52mm speaker! Why not just call it a 52,000,000 nm speaker?) The sounds are typically monophonic and generated in real time (“non-looping”) by an approximation algorithm.
Generating sounds in real time is actually not a bad idea for something constant like white noise or pink noise. In fact, my colleague Tomas has an excellent white noise generator currently available on balenaHub. A fan or air cleaner is also a great way to generate constant noise. A few noise machines do use an internal fan-like system and those seem to work well if that’s the only sound you need.
However, my requirements for a noise machine are somewhat steeper:
- Must produce CD-quality stereophonic audio.
- Use real audio samples with gapless undetectable looping
- A high quality amplifier and speaker system and/or line level audio output
- Intuitive control panel with rotary wheel and LCD screen
- Web-based control with a responsive UI for any client
Here’s my initial plan for the ultimate noise machine, a ridiculously over-engineered device running on a Raspberry Pi 3B+ and taking advantage of many features of the balena platform:
I’ve decided to forego an internal amplifier/speaker initially to keep things simpler, and use a line out jack to connect a powerful amplified speaker with subwoofer.