Speech spectral intensity discrimination at frequencies above 6 kHz

Hearing aids and other communication devices (e.g., mobile phones) have made some recent efforts to extend their bandwidths to represent higher frequencies. The impact of this expansion on speech perception is not well characterized. To assess human sensitivity to speech high-frequency energy (HFE, defined here as energy in the 8- and 16-kHz octave bands), difference limens for HFE level changes in male and female speech and singing were obtained. Listeners showed significantly greater ability to detect level changes in singing vs. speech, but not in female vs. male speech. Mean differences limen scores for speech and singing were about 5 dB in the 8-kHz octave (5.6–11.3 kHz) but 8–10 dB in the 16-kHz octave (11.3–22 kHz). These scores are lower (better) than scores previously reported for isolated vowels and some musical instruments, and similar to scores previously reported for white noise.