Audio frequencies are a measure of how low or high the pitch of a sound is. A bass sound or a rumble is described as having a low frequency, whereas a flute or a scrape is far more of a high frequency. All these sounds will contain acoustic energy at many frequencies, rather than at just one, but the ‘dominant’ and ‘important’ frequencies usually help us describe its quality as low- or high-pitched.

For a larger, more in-depth guide to audio frequencies and how to treat them, read our guide to Understanding Frequencies in Audio: Getting Perfect Sonic Character.

What’s the frequency range of the human voice?

When applied to speech, the human voice spans a range from about 125Hz to 8kHz. It’s no coincidence that this range puts the voice in the center of the range of human hearing – early humans who were more attuned to this frequency range were more able to understand others and more likely to survive and thrive.

Different areas of this frequency spectrum fulfil different functions in our speech: the lowest parts help us to identify pitch and therefore speech intonation; the consonants change the meaning of a word (‘cat’ and ‘bat’ are different things); and the vowels help us recognise one speaker from another, as well as changing the sounds of letters, of course.