High-frequency squeak from electrical devices

To emit a squeak can be heard as transformers, capacitors, inductors, and other components of electronic devices. While this selectivity in the perception of children and animals due to the peculiarities of hearing. The auditory analyzer perceives the acoustic waves with frequencies from 20 Hz to 20 kHz. Different people and even the same individuals at different times, the hearing threshold may vary. It depends on age, physiological state, of fitness. With age people stop hearing high frequency.
There are special programs-generators that play the sounds of different frequencies and to determine the level of hearing particular person, but to use them only if you have good equipment that reproduces the sounds of the desired band of frequencies.

Translated by «Yandex.Translator»