You may be interested to know that the latest versions of the firmware for the ARM946 based Fastrack Supreme, Q26 Series and WMP100 support a very cool new feature called OAP (Open Audio Path - not Old Aged Pensioner!). Here’s a brief description:
Open Audio Path: “Although M2M applications usually use data channels, having full control over the audio chain can be very useful. Therefore, Wavecom has opened the Audio Path to let you do whatever is requested for your solution - from Audio sniffing, playing and recording to equalizing.”
That means you can tap in to the DSP audio flow with new Open AT APIs to listen, record, playback, and even inject your own audio streams into the GSM audio channel.