Audio Test Tones
In downloadable ZIP files.
- Blue Noise Blue noise is randomly occurring noise having a power density that increases 3dB per octave with increasing frequency (density proportional to frequency) over a finite frequency range. This can be good noise for dithering.
- Brown Noise Brown noise is a randomly occuring noise that exhibits a power density that decreases 6dB per octave with increasing frequency (density proportional to 1/frequency squared) over a frequency range which does not include DC. It is not named for suggesting the color brown. The name is a corruption of Brownian Motion. AKA "random walk" or "drunkard's walk" noise. This can be good noise for electronic synthesis of bass sounds.
- Three Tone Bursts Three tone bursts of 100 Hz, 1,000 Hz and 10,000 Hz. Useful for setting up echo, reberberation or delay processors, acoustics testing, transient response testing, and electronic synthesis of percussive sounds.
- 7,350 Hz IMD test tones Standard test tones for audio testing of intermodulation distortion.
- SMPTE IMD Test Tones Standard test tones for audio testing of intermodulation distortion in accordance with standards established by the Society of Motion Picture and Television Engineers, or SMPTE.
- Pink Noise Pink noise is randomly occurring noise power density that decreases 3dB per octave with increasing frequency (density proportional to 1/frequency) over a finite frequency range that does not include DC. Each octave contains the same amount of power. AKA flicker noise. Used for acoustic testing and sound masking applications.
- Square Waves A small collection of square waves for audio testing or electronic synthesis.
- Linear Sweep sine waves swept from 20 hz to 20,000 Hz for audio testing.
- Violet Noise Violet Noise is randomly occurring noise that exhibits a power density that increases 6dB per octave with increasing frequency (density proportional to frequency squared) over a finite frequency range. Differentiated white noise. AKA purple noise. This can be good noise for dithering.
- White Noise White noise is randomly occurring noise having a power density that is constant over a finite frequency range. AKA Johnson noise. Useful for audio testing, tape hiss cancellation processing, and sound masking.
- 2960 Hz Steady sine wave tone to set tape deck speed by ear. Play it on your computer speakers, then set the tape deck's speed control like you would tune an instrument.
- 3000 Hz Steady sine wave tone to set tape deck speed by ear. Play it on your computer speakers, then play a speed test tape that has a 3 Khz (3000 Hz) tone. Compare the two tones, then set the cassette deck speed control like you would tune an instrument -- in other words, match the tone played by the tape deck to the tone played through the speakers.