Simple Explanation

The range of sound that humans can hear, from very low bass to high treble.

Concise Technical Definition

The range of frequencies between 20 Hz and 20,000 Hz (20 kHz), corresponding to the limits of typical human hearing.

Layman-Friendly Analogy

Think of audio frequency like the keys on a piano—from deep, rumbling bass notes to sharp, high-pitched ones.

Industry Usage Summary

Audio frequency (AF) is a foundational concept in audio design, used in equalizers, filters, crossovers, and speaker tuning. The spectrum is often divided into sub-bands: sub-bass, bass, midrange, upper mids, and treble.

Engineering Shortcut

AF = 20 Hz to 20 kHz range; the audible sound band.

Full Technical Explanation

Audio frequency refers to the portion of the sound spectrum audible to the average human ear, generally spanning from 20 Hz (deep bass) to 20,000 Hz (high treble). This range includes all musical notes and most speech frequencies. Audio systems are designed to reproduce this band accurately, and many measurement tools (like frequency analyzers) are calibrated within this range. While some individuals may hear slightly outside this range, most audio equipment focuses on this defined band for consistency, clarity, and performance.