amixer

Turn up the master volume by 10%

$ amixer -D pulse sset Master 10%+

$ amixer -D pulse sset Master 10%-

$ amixer -D pulse sset Master mute

$ amixer -D pulse sset Master unmute

$ amixer scontrols

amixer [-option] [cmd]

amixer is a command-line mixer control for the ALSA soundcard driver. It can adjust volume levels, toggle mute states, and query mixer control settings for any available soundcard. Running it without arguments displays current mixer settings for the default soundcard.
The tool provides both simple and full mixer interfaces. The simple interface (commands prefixed with s) uses human-readable control names like "Master" or "PCM", while the full interface operates on numeric control identifiers. Volume can be specified as absolute values, percentages, or decibels.

-c card

Select card number (e.g., 0, 1, 2)

Select device name (default: 'default')

Read and execute commands from stdin sequentially

Quiet mode; suppress output

Raw value for percentage evaluation (default)

Mapped volume for percentage evaluation

scontrols

List all simple mixer controls

List simple mixer controls with their contents

Configure mixer control contents (supports percentage, dB values, mute/unmute/toggle)

Display simple mixer control contents

List all card controls

List card controls with their contents

Show mixer device information

Mixer control names vary between sound cards. Use scontrols to list available controls for your card.

Part of ALSA (Advanced Linux Sound Architecture) utilities package.

alsamixer(1), aplay(1), arecord(1)