amixer

amixer is a command-line mixer for the ALSA (Advanced Linux Sound Architecture) sound system. It is part of the alsa-utils package and provides a text-based interface to view and modify mixer controls on Linux systems. The tool can report current control values, mute status, and allow adjustments to volume, capture levels, and other parameters exposed by the sound card.

Controls are organized into simple and more complex types. Simple controls can be queried and set with sget and sset, while more advanced controls may require different syntax. Common actions include listing available controls with amixer scontrols or amixer controls, querying a control with amixer sget Master, and changing values with amixer sset Master 70% or amixer set Master 70%. Volume can also be adjusted relatively using amixer sset Master 5%+ or 5%-, and mute or unmute can be toggled with appropriate commands.

You can target a specific sound card with the -c option or specify the mixer device with -D. For example, amixer -D pulse sget Master can be used on systems employing PulseAudio, though PulseAudio maintains its own separate volume management.

amixer is widely used in scripts and system administration to automate volume control, mute status, and capture level adjustments. It remains a standard tool in many Linux distributions and is documented within the ALSA project resources, reflecting its role in configuring and diagnosing audio behavior at the command line.