Composite speech spectrum for hearing and gain prescriptions.

Average long-term RMS 1/3-octave band speech spectra were generated for 30 male and 30 female talkers. The two spectra were significantly different in both low and high frequency bands but were similar in the mid-frequency region. It was concluded that a single spectrum could validly be used to represent both male and female speech in the frequency region important for hearing aid gain prescriptions: 250 Hz through 6300 Hz. In addition, the male and female spectra were compared with analogous spectra reported by Byrne (1977) and Pearsons, Bennett, and Fidell (1977). For each sex, significant differences were found among the three spectra in a few frequency bands. The best estimate of the average speech spectrum for each sex was obtained from a weighted average of the three sets of data, excluding the significantly different data points. The long-term RMS 1/3-octave band speech spectrum for male and female talkers combined was derived for use in hearing aid gain prescriptions.