Reference tone

1000 Hz — 1 kHz Reference Tone

1 kHz is the audio industry's universal reference tone — used for level calibration, line-up tones and equipment testing.

Audio visualization
Hz

 

20 Hz20 kHz
Waveform
Volume50%
L/R BalanceCenter

Press Space to play

About the 1000 Hz tone

A 1000 Hz sine wave is the go-to signal for setting and checking audio levels. Broadcast and studio “line-up” tones are almost always 1 kHz, because meters and the ear are both well-behaved at that frequency.

It's also handy for a quick channel check: play the tone and use the balance control to confirm your left and right speakers or headphones are both working and roughly matched.

Because 1 kHz sits in the most sensitive part of human hearing, it makes a reliable tone for confirming that a signal chain is passing audio at all.

Technical details

Frequency
1000 Hz
Nearest note
B5 (+21¢)
Category
Reference tone
Period
1.00 ms
Wavelength (air)
34.3 cm
Octave up / down
2000 Hz / 500 Hz

Common uses

  • Set or check audio levels (line-up / reference tone)
  • Test speakers, headphones and audio interfaces
  • Confirm left/right channels with the balance control

Nearby frequencies