亚马逊AVS开发，外接麦，需要修改配置文件，添加配置。
#Edit alsa config file as shown
sudo vi /usr/share/alsa/alsa.conf
defaults.ctl.card 1
ddefaults.pcm.card 1
defaults.pcm.device 0
defaults.pcm.subdevice 0
#These card values are for USB Mic andRpi's 3.5mm jack audio out.
sudo vi ~/.asoundrc
pcm.!default {
type asym
playback.pcm {
type plug
slave.pcm "hw:0,0"
}
capture.pcm {
type plug
slave.pcm "hw:1,0"
}
}
ctl.!default {
type hw
card 0
}
#Copy paste the above settings inasound.conf as well
sudo vi /etc/asound.conf