MedRx AVANT REM (Real Ear Measurement) Training Manual
Effective Date: 05-25-2017
17
Pink
The noise is filtered so its energy per frequency (power spectral density) is inversely
proportional to the frequency. Each octave carries the same amount of energy. Comparing to
White Noise, the Pink Noise energy drops approximately 3dB per octave.
Pink-weighted noise can be used mostly for testing of equipment. It is not recommended to
use it for hearing aid fitting, unless specified by the manufacturer.
Crest Factor: BBN = 3.67 (11.3dB), PRN = 6.55 (16.3dB)
Speech - Byrne
The noise is approximately weighted to International Long Terms Average Speech Spectrum
(ILTASS) as described in Byrne et. al., 1994.
The noise with this weighting is preferred for hearing aid fitting because its spectrum is the
best approximation of the spectrum of real human speech.
Crest Factor: BBN = 4.22 (12.5dB), PRN = 3.47 (10.8dB)
Speech - ANSI
The noise is approximately weighted to ANSI S3.42 Speech Noise.
The noise with this weighting can be used for fitting hearing aids. The slope of ANSI-weighted
noise is not as steep as Byrne-weighted, so there is more power in higher octaves. This will
result in less gain required by the hearing aid to reach targets, but may result in under-fitting
at high frequencies.
Crest Factor: BBN = 4.46 (13.0dB), PRN = 5.17 (14.3dB)
