There's a few ways you can do this. The cheapest is to just get a laser and a photo diode. It's rough, but you can get sounds. An interferometer works better. It's harder to make and more expensive, but in the hobby range, at least to get decent quality. There's tons of videos and documents that you can find showing you how to make either. You can also do a lot of cool measurements with these setups
The design is extremely simple. The hard part is aligning things. That's actually the hard part about most optics. If you're really OCD you need to be even more.
