#audio frequency

• Audio frequency — The frequency of an acoustic wave or an alternating electrical signal falling within the spectrum perceptible by the normal human ear, located between the approximate limits of 20 Hz and 20,000 Hz; audio frequency. In electronics, it defines the oscillation band processed by amplifiers and speakers.
• Audible — Capable of being heard; whose mechanical vibrations fall within the limits of frequency (usually between 20 and 20,000 Hertz) and intensity perceptible by the human auditory organ; audible, perceptible.