Sound

Useful applications for software DSP

• Echo cancelling for audio conferencing, kareoke
• Use of VST plug-ins or other callback based software DSP: Robot voices, vocoder, delay, flanger.

Further research

Open source allback based software DSP. Have found these before.

• Review notes and links

Hardware sound drivers

• ALSA

Synchonous callback based audio server

• jackd

Troubleshooting

Here are some commands that will allow you to test the audio system for correct operation.

• alsamixer - ANSI GUI to the ALSA mixer controls (VERY USEFUL)
• lsmod - lists current kernel modules and what they are used for (VERY USEFUL)
• aplay - play some sound
• amixer
• vi .asoundrc - edit the ALSA configuration file usually found in ~
• lspci - list current PCI interfaces
• alsactl store|restore - lets you save|load the current ALSA driver settings
• speaker-test - play some pink noise and cycle through available channels

Resources

• jackd - the audio server http://jackit.sourceforge.net/
• amsynth - emulation of an analogue synthesiser http://amsynthe.sourceforge.net/amSynth/
• Debian sound configuration http://xtronics.com/reference/Debian-sound.html