Downloadable reference signals for basic acoustical checks, system testing, demonstrations, and troubleshooting. Noise and tone files are generated as 30-second mono 48 kHz / 16-bit WAV files; the full-scale impulse file is 10 seconds. No registration is required.
Level caution: Start playback at a low volume. Pure tones and broadband noise can become uncomfortable or damaging at high playback levels.
Broadband Noise
White Noise
Equal energy per hertz; useful for broad-spectrum testing.
Pink Noise
Approximately equal energy per octave; commonly used for audio and room testing.
Brown Noise
Stronger low-frequency emphasis than pink noise.
Pure Tones
125 Hz
Low-frequency sine-wave reference tone.
250 Hz
Low-mid-frequency sine-wave reference tone.
440 Hz — Concert A (A4)
Standard A4 tuning reference.
500 Hz
Mid-frequency sine-wave reference tone.
1 kHz
Common calibration and audio reference tone.
2 kHz
Upper-mid-frequency sine-wave reference tone.
4 kHz
High-frequency sine-wave reference tone.
8 kHz
High-frequency sine-wave reference tone.
Channel Identification Tracks
Stereo 2.0 — Left / Right
Two-channel WAV with a short 1 kHz identification tone first in the left channel, then in the right channel.
5.1 Surround Channel Identification
Sequential 1 kHz tone bursts: Front Left, Front Right, Center, LFE, Surround Left, Surround Right.
7.1 Surround Channel Identification
Sequential 1 kHz tone bursts: Front Left, Front Right, Center, LFE, Back Left, Back Right, Side Left, Side Right.
Impulse / Reverberation Test Signal
Full-Scale Digital Impulse — 0 dBFS Peak
A single-sample full-scale impulse followed by silence, intended for room/system impulse-response and reverberation-decay checks when reproduced through a suitable loudspeaker system.
Use caution: begin with playback gain very low. A full-scale impulse has extremely high crest factor and can stress loudspeakers or produce unsafe acoustic levels if reproduced carelessly.
About These Files
These signals are provided as convenient general-purpose references. They are not a substitute for a calibrated acoustic source, calibrated instrumentation, or the signal requirements of a specific ASTM, ANSI, ISO, IEC, OSHA, or project test procedure.
