• Как в Raspberry Pi 3 Model B настроить режим вывода аудио
• How to test microphone with Audio Linux Sound Architecture

# dmesg | grep snd

# apt install alsa-utils

# init 6

# wget http://val.bmstu.ru/unix/Media/bird_1.au

# aplay bird_1.au

# aplay -l
card 0 ... device 0
...

# amixer cset numid=1 -- 100%
# amixer cset numid=2 -- 100%

# aplay --device="hw:0,0" bird_1.au

# arecord -l

# arecord -f S16_LE -d 10 -r 44100 --device="hw:0,0" -c 2 filename.wav

# aplay filename.wav

• Настройка звуковой карты

# cat /dev/sndstat

# ls /dev/dsp0.0 # auto created

# ls /boot/kernel/snd_*

oldfreebsd# kldload snd_driver

# cat /dev/sndstat

Installed devices:
pcm0: <Intel ICH (82801AA)> (play/rec) default

• Управление ядром и модулями в FreeBSD

# fetch http://val.bmstu.ru/unix/Media/bird_1.au

# file bird_1.au

bird_1.au: Sun/NeXT audio data: 8-bit ISDN mu-law, mono, 8000 Hz

freebsd8# cp bird_1.au /dev/audio0.0

freebsd10# cp bird_1.au /dev/dsp0.0