m-calculator | My personal beauty scientific calculator made with Expo | Apps library

Based on your code, it seems your mixing Async/Await with Promises. It is recommended that you pick only one for your code.

Try something like this, using only Promises, for example:

Reading the .wav file

The .wav file decoding included in that other question you linked is hardly a full blown decoder. It accounts for the OP's specific stereo 2bytes-per-sample use-case.

It looks like you stumbled upon other decoding issues while trying to adapt it to a different use case. As a general piece of advice, I'd suggest to use a more complete .wav decoder which would take into account the number of channels, the number of bytes-per-sample, etc.

If on the other hand you want to craft your own decoder (for example as a learning exercise), then a slightly more robust implementation may look like the following:

You can XOR pairs of the the samples to reduce the number of variables, since this eliminates any initial value or final xor (as if both were 0), and a search only needs to look for the polynomial and if it's non-reflected (left shifting) or reflected (right shifting). For CRC16, that's only 64k loops for left shift and 64k loops for right shift. It's possible to get multiple polynomials that appear to work, so more samples are needed to confirm.