rmfc wrote:
I'm trying to use any USB sound card with some DSP processing that allows a microphone array to capture audio and use in speech recognition (mostly applied in noisy environments). The best device that I found so far is AndreaElectronics PureAudio USB-SA but unfortunately it isn't properly supported in Linux/Alsa. The device is recognized as an USB Audio device (snd_usb_audio) and I can record audio in Audacity. The problem is that none of DSP features is explicitly activated in USB configuration so it works almost like any other microphone. I then tried Asus Xonar U1 but the problem is the same, no configuration is done in such devices, so they record audio without enough quality to be used by a speech recognizer (not enough energy, audio DC components when software gain is applied in Sound Preferences...).
Neither of these device has a DSP; any processing is done in software in the Windows driver.
Regards, Clemens