Mechanical Engineering Commons^™

The spectral center of gravity refers to a listener’s averaging of frequency and intensity components when formant peaks in a speechlike signal are separated by 3.5 Bark units or less. In this paper a total of 18 synthetic vowels whose spectra approximated /ae/ or /inverted vee/ were generated digitally; each stimulus contained the first 40 harmonics of a 100‐Hz fundamental. Nine spectra contained three formants, while the balance contained only two. Subjects with normal hearing and mild high‐frequency hearing loss above 3000 Hz were instructed to identify synthetic vowels as either /ae/ or /inverted vee/ as F2 frequency was …

Click‐evoked otoacoustic emissions (CEOEs) were collected from 167 ears of 106 normal‐hearing children using the ILO88 system with the stimuli presented at 80±2 dB pe SPL. Subjects were divided into five age groups: 13–24 months (24 ears), 25–36 months (49 ears), 37–48 months (31 ears), 49–60 months (34 ears), and 61–72 months (29 ears). All subjects had normal middle ear function and their audiological data were within normal limits. Mean overall CEOE level was calculated for each age group. None was statistically different from any other. However, the data of the 167 ears showed small but statistically significant decrease in …