Binaural beat generator — set the carrier and the beat

How to use the binaural beat generator

1. Put on headphones and turn your device volume down.
2. Enter the Carrier tone (40–1,500 Hz, default 200) and the Beat (difference) (0.5–40 Hz in steps of 0.5, default 10). The readout above shows the exact left and right frequencies.
3. Press Play. The sound fades in over 2 seconds. You can change the carrier, beat and Volume (1–60%, default 15%) while it plays; the tones glide to the new values.
4. Press Stop for a gentle 1.5-second fade out.
5. To save it, set Export length (5 to 7,200 seconds) and press Export WAV.

What it does and when to use it

The tool gives you full control over the two numbers that define a binaural beat, instead of a fixed set of presets. People use it to hear the effect for themselves, to make a background track for meditation or study, or to prepare test material for a class or an experiment about how the brain combines sounds from both ears.

Low carriers (around 100–250 Hz) sound soft and warm, while high ones sound thin, so try a few to find a pair you can listen to comfortably. For a plain single tone use the tone generator; for a steady masking sound try pink or brown noise in the noise generator.

How it works

The left channel plays a sine wave at carrier − beat ÷ 2 and the right channel at carrier + beat ÷ 2:

left = carrier − beat / 2, right = carrier + beat / 2

During playback, two Web Audio oscillators are joined into one stereo signal in your browser. The export calculates the same two sine waves sample by sample at 44,100 samples per second and adds an equal-power fade at the start and end (2 seconds, or a third of the length if that is shorter). Nothing is uploaded.

Worked examples

These figures come from the tool’s own export function.

• Default. Carrier 200 Hz, beat 10 Hz: left ear 195 Hz, right ear 205 Hz. The 60-second file is binaural-200hz-10hz-beat-60s.wav.
• A slow beat for a long session. Carrier 400 Hz, beat 4 Hz, 1,800 seconds: left 398 Hz, right 402 Hz, saved as binaural-400hz-4hz-beat-1800s.wav (about 302.8 MB).
• Decimal values. Carrier 136.1 Hz, beat 7.5 Hz: left 132.35 Hz, right 139.85 Hz.

Limits and tips

• Sine tones only. There is no background music or noise layer. To add one, mix the WAV in an audio editor.
• Long exports are large and are built in your browser’s memory; on a phone, export 10–20 minutes and loop it in your player instead.
• Make the file smaller by converting it to M4A or Opus with the audio converter. Keep it stereo; a mono file loses the effect.
• Check the channels with the audio playback tester if the beat seems missing.