Adjusting the mic sensitivity while recording audio in android

Question

I am developing an android application which records audio in PCM using the AudioRecord API. I want to adjust the mic sensitivity to low, medium and high as the user chooses it in the settings.

Is it possible to adjust the mic sensitivity? Your answers will be highly appreciated :)

Answer 1

Not really. It's usually possible to get at least two different "sensitivities" (acoustic tunings used by the platform) implicitly by using different AudioSources.
There should at least be one tuning for handset recording and one for far-field recording. On some devices you might also have different far-field tunings, e.g. one for recording audio a few decimeters away and one for recording audio a few meters away.

The problem is that you can't really know which AudioSource corresponds to which tuning, as there's no standard for it. CAMCORDER typically means far-field, and VOICE_RECOGNITION often means handset mode, but there's no guarantee for it. You should also keep in mind that vendors typically apply automatic gain control, noise reduction, etc that you as a user / app developer can't disable, in order to meet acoustic requirements for their products.

Your best bet would probably be to use a single AudioSource and then do attenuation of the signal in your app to simulate a lower mic sensitivity. You could do amplification as well, but that would be akin to using digital zoom in the camera app (it works, but doesn't look all that good because you're just scaling the existing data).