Test Tone

A tone of a certain waveform sent at a predetermined level and frequency which is used for test purposes, such as for facilitating measurements, or to help determine the optimum placement for speakers, to measure SPLs and for aligning gains and losses in an audio system. A test tone is theoretically a constant pure wave of the desired waveform. In practice, many test tones are not perfectly shaped, and the quality of the test tone produced is generally directly proportional to the quality of the device (usually some type of oscillator) being used to produce it.