How to add/replace an usb sound card
linaro-nano:~> lsusb
Bus 001 Device 006: ID 1395:0025 Sennheiser Communications
Bus 001 Device 004: ID 04f2:0402 Chicony Electronics Co., Ltd Genius LuxeMate i200 Keyboard
Bus 001 Device 003: ID 093a:2500 Pixart Imaging, Inc. USB Optical Mouse
Bus 001 Device 002: ID 1a40:0101 Terminus Technology Inc. 4-Port HUB
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
linaro-nano:~> aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: monitor [HDMI monitor], device 0: HDMI adv7511-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
the usb "sennheiser..." headset is connected, but not listed by aplay..
how to introduce it ?