gavin@lappy486:~$ lsusb
Bus 003 Device 001: ID 0000:0000  
Bus 002 Device 001: ID 0000:0000  
Bus 001 Device 003: ID 046d:0a02 Logitech, Inc. 
Bus 001 Device 001: ID 0000:0000  
gavin@lappy486:~$ cat /proc/asound/cards
 0 [SB             ]: HDA-Intel - HDA ATI SB
                      HDA ATI SB at 0xd0400000 irq 19
 1 [Headset        ]: USB-Audio - Logitech USB Headset
                      Logitech Logitech USB Headset at usb-0000:00:13.0-1, full speed
gavin@lappy486:~$ cat /proc/asound/devices
  2:        : timer
  3:        : sequencer
  4: [ 1- 0]: digital audio playback
  5: [ 1- 0]: digital audio capture
  6: [ 1]   : control
  7: [ 0- 6]: digital audio playback
  8: [ 0- 6]: digital audio capture
  9: [ 0- 1]: digital audio playback
 10: [ 0- 0]: digital audio playback
 11: [ 0- 0]: digital audio capture
 12: [ 0]   : control