This is a base system framework update, which gives enhanced sound processing capabilities to 2.2-based phones. A simple application called DSPManager is provided to adjust the new audio parameters.



Dynamic Range Compression
The power of signal is estimated by calculating the mean of the sample data. The mean is converted to decibels, and adjusted to the DRC curve. The current curve is simply linear, mapping the original -96 dB–0 dB range to some smaller region such as -48 dB—0 dB (factor 2.0:1). Once a correction is established, it is applied along the track's volume control.
Equalizer
Biquad-based audio filter. 3 peaking band equalizers are spaced 4 kHz apart starting from 250 Hz, and a final shelve adjusts the treble band. Bass is emulated as global gain, and compensated by the other sliders.
Headphone Virtual Room Effect
A delayed, phase modified and lowpass-filtered version of the opposite channel is added to the current channel. The processing pipeline is pure delay, 3 all-pass filters of varying delays, and the final lowpass filter. The theory is that the audio from the other ear takes longer to reach the other ear, and is partially obscured by the head resulting in the lowpass filtering. The allpass filters decorrelate the phase of the other audio stream, which makes the filter seem more natural for some psychoacoustic reason.

you guys can download here http://bel.fi/~alankila/android-dsp/