How to detect volume from microphone?

[wiso33]

Hi,everyone. I want to done such a game: A girl will doing each postures with volume from microphone, e.g. She will dancing if shout loudly toward microphone. She will smiling if low voice. She will sleeping if Silence.

How to detect volume from microphone real time.

[wizard_hu_]

Simply get some samples from any recorder API, like CMdaAudioRecorderUtility or CMdaAudioInputStream, calculate some loudness (RMS or average-of-absolutes over some short time), and compare it to various threshold values.

[wiso33]

Thank for reply. And how to calculate loudness in sample data.

[wizard_hu_]

The tool is called mathematics.
RMS: http://en.wikipedia.org/wiki/Root_mean_square
"Average-of-absolutes": http://en.wikipedia.org/wiki/Absolute_deviation

Of course you can bring in extras like Fourier transformation, and weight the result according to the human hearing.

[wiso33]

In fact, I don't need exact loudness value. I need a threshold values to on-off enough. I wonder if there is a simple api to use in s60 sdk.