Psophometer

In telecommunication, a psophometer is an instrument that provides a visual indication of the audible effects of disturbing voltages of various frequencies.

Note: A psophometer usually incorporates a weighting network[?]. The characteristics of the weighting network depend on the type of circuit under investigation, such as whether the circuit is used for high-fidelity[?] music or for normal speech.

Source: from Federal Standard 1037C