Detect human voice from audio file input

Question

I am trying to implement automatic voice recording functionality, similar to the Talking Tom app. I use the following code to read input from the audio recorder and analyse the

Answer 1

In the completely general case, this is an unsolved problem. In the practical sense...

First step is to get as noise-free a recording as possible. As others have noted, that starts with a directional microphone as focused on the sound you want to keep as possible.

Second step is filtering. As noted previously, the telephone company did a lot of work on which frequency ranges are actually needed by humans for speech comprehension. Filtering out frequencies outside that range will make the voice sound like... well, a telephone... but will get rid of more of the background noise.

If you want to go beyond that, things can get really complicated. There are some algorithms which, if you can show them a sample of what you consider noise on that particular recording, will analyse it and try to subtract it out without damaging the sound you want to keep too much. This is not simple programming; if I were you I'd seriously consider buying it from someone who has already gotten it right rather than trying to reinvent/reimplement it. I don't know whether any of them are available for Android or whether the typical Android box has enough computing power to execute them in anything like realtime. (I've used SoundSoap in the studio to remove A/C noise, and it works very well.)

In fact, my own inclincation would be to simplify the problem to a solved one: use the most directional and closest mike I could get, let Android do the recording... but then do the signal processing to clean it up later, using off-the-shelf tools. But I admit I'm biased because I have already invested in the latter.