Audio transducers and buzzers are used in electronic equipment, toys and various warning devices as the sounding component

VU meters measure the volume (intensity) of analog audio signals.

Audio mixers and consoles are units that combine signals from microphones and/or line level sources to produce a combined signal or signals

Frequency meters are instruments that provide analog outputs as frequencies that vary as a function of the applied input.

Sound level meters and noise dosimeters are used in sound and noise analysis.

Phase meters (phase testers, phase rotation meters) check the phase sequence and phase orientation in three-phase electrical systems

Audible alarms provide an audible indication of a hazardous situation.