ALSA

ALSA or the Advanced Linux Sound Architecture provides audio support for Linux. It is a replacement for the old OSS linux sound system. The Alsa-utils package contains both the Alsamixer and Amixer utilities. Various linux distributions once used the Open Sound System, or OSS until ALSA superseded it. ALSA provides kernel driven sound card drivers and bundles a user space driven library for application developers.

You can control the audio properties of your sound cards through:

• Alsamixer-The graphical interface for ALSA
• Amixer-The command based utility for ALSA

CLI Utilities

alsamixer

ncurses based utility with visual representation of various levels.

alsamixer

Enable the microphone: switch to the Capture tab with F4 and enable a channel with Space.

mixer

Command line, operation performed per command.

amixer -c [card-number] set [control] [value]

To see what controls you can manage

amixer scontrols

If you are sudo there are more controls available

sudo amixer scontrols

apulse

The apulse utility lets you use ALSA for applications that support only PulseAudio for sound.

aplay

Alsa play - play an audio file

speaker-test

as the name implies