Impedance Audiometry With Neonates

High-Frequency (1000 Hz) Tympanometry in Normal Neonates

“…In con-trast, 47.5 % (116/244) of ears exhibited the double-peaked pattern when the 226 Hz probe tone was used (see Figure 5). These findings are in agreement with that reported by Keith (1973), Sprague et al (1985) and Holte et al (1991), who found that the occurrence of doublepeaked tympanograms and .the complexity of shapes decreased as the frequency of the probe tone was increased.…”

The hepatitis C virus-associated dysmetabolic syndrome

“…The main reason for this difference is the age distribution of the study group. The average age of patients in the current study is 12.3 months, obviously younger than those of Watters et al Although tympanometry has proved to be important for detecting effusion and other middle ear problems, it produces differently shaped tympanograms in infants compared to adults and older children 17–19…”

Further Questions about the Acceptable Noise Level Test

“…Other data confirm that at 220 Hz, reflexes are seen either infrequently or not at all (Bennett 1973;Keith 1973;Keith and Bench 1978;Stream et al, 1978;McMillan et al, 1985), but they are at higher probe tones Bennett, 1980, Bennett andWeatherby, 1982;Sprague et al, 1985;McMillan et al, 1985;Geddes, 1987). More recent work has confirmed Weatherby and Bennett's model and that the very young infant drum has a lower resonance frequency and its middle ear is mass-rather than stiffness-dominated, developing into a more adult system with a transition around four months (Holte et al, 1991;Keefe and Levi, 1996;McKinley et al, 1997;Meyer et al, 1997).…”