Pure tones are the standard audiometric stimulus because they are frequency-specific.

Evidence

When carrying out an audiometric test, local sound levels should be below the levels defined in BS EN ISO 8253–1, which are shown for the test frequencies in Figure 7.35. Generally, the local level should be below 35 dBA. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2344 (#expands, via linked claim)

Categorization

• XREF: connects to: Hearing thresholds are defined for steady tones lasting over 100 ms; Hearing thresholds are clinically tested at octave-spaced frequencies covering the speech range; The auditory system acts as a band-pass filter at each signal frequency. (+1 more)

Broader Connections

• Hearing thresholds are defined for steady tones lasting over 100 ms #expands (0.75)
• Hearing thresholds are clinically tested at octave-spaced frequencies covering the speech range #expands (0.72)
• The auditory system acts as a band-pass filter at each signal frequency. #corroborates (0.72)
• Audiometric testing requires ambient sound below 35 dBA with frequency-specific limits #expands (0.72) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2344