How to create sound clips when silent?

Question

So I am writing a program that splits an audio clip up into multiple parts when no sound is playing. So that all the clips created from the sound file only contain sections with sound. How would I accomplish this using Java? I plan on using FLAC, but the program currently supports WAV as well. Would RMS be the best way to determine this? Bonus points for any code.

Answer 1

You can roughly approximate the 'loudness' of a sampled waveform by averaging the squares of the differences between samples n and n+1. This will give you a rough indicator of how "loud" these samples will appear to the hearer.

The method is more sensitive to high frequencies than low ones, thats why it can be off quite a bit if the sound has a very extreme frequency distribution.

For a precise solution you will need to take the FFT approach and also correct the extracted frequencies weighting by a model representing the hearers ear (not all frequencies feel equally loud at the same DB level).