Audio Tools
Convert audio files and measure sound.
Measure approximate ambient sound levels using your microphone — with an honest statement that a phone microphone is not a calibrated instrument.
Audio ConverterConvert audio between formats in your browser — MP3 to WAV, WAV to MP3 and more — with a clear account of what each conversion costs.
Tone GeneratorPlay a pure tone at any frequency to test speakers, hearing and tuning — with a clear warning about volume and hearing damage.
White Noise MachinePlay white, pink and brown noise plus rain sounds to focus, relax or sleep — with what actually distinguishes the colours.
Voice RecorderRecord audio from your microphone and download it, entirely in your browser — nothing is uploaded and no account is needed.
Online Hearing TestTest the range of frequencies you can hear, from deep bass to high treble — a rough indication only, and explicitly not a hearing assessment.
About these audio tools
The decibel confuses people because it is a ratio on a logarithmic scale, and almost every intuition about it is off by a factor. Doubling the power of a signal adds three decibels. Doubling the amplitude adds six. But doubling the perceived LOUDNESS takes about ten decibels, which is ten times the power. So a hundred watt amplifier is not twice as loud as a fifty watt one — it is roughly a quarter louder, and reaching genuinely twice as loud from fifty watts needs five hundred. That single mismatch explains most disappointment about amplifier upgrades, and it is why speaker sensitivity, measured in decibels per watt, buys more loudness per pound than amplifier power does. The second thing worth knowing is that decibels are meaningless without a reference. dB SPL is referenced to the quietest audible pressure, dBFS to digital full scale, dBu and dBV to particular voltages. Minus eighteen dBFS and plus four dBu can describe the same signal, and a number quoted without its suffix is not a measurement. The third is that digital headroom works in the opposite direction to analogue. On tape, pushing past nominal level gave gradual and often pleasant saturation. In digital there is a hard ceiling at zero dBFS and nothing above it — samples that would exceed it are clipped flat, producing harmonic distortion that no later processing removes. That is why recordings are tracked with peaks well below the top of the meter, and why a mix reading as loud on a meter can have almost no dynamic range left to give.