树莓派麦克风

问题1：

down vote

If you don't need the onboard audio chip (i.e. analog output or hdmi audio), try this:

1. Disable onboard audio.
   • Open /etc/modprobe.d/raspi-blacklist and add blacklist snd_bcm2835.
2. Allow the USB audio device to be the default device.
   • Open /lib/modprobe.d/aliases.conf and comment out the line options snd-usb-audio index=-2
3. Reboot
4. Test it: $ aplay /usr/share/sounds/alsa/Front_Center.wav

问题2：

As far as I know Flash only outputs sound to the default ALSA device, which is usually the first detected by ALSA. One way (and the only that worked reliably for me when i used 2 sound cards) of setting another device as default is in a ~/.asoundrc file. You will probably have to create the file as it is not normally used. 

Code:

pcm.!default {type hwcard 1}ctl.!default {type hwcard 1}

These might need changing depending on your cards.

aplay -l will list all configured ALSA sound devices on your machine, which I see you have done.