Robert H. Margolis

Effects of Otitis Media on Extended High-Frequency Hearing in Children:

Extended high-frequency (EHF) hearing was studied in children with and without histories of chronic or recurrent otitis media (OM). The EHF thresholds were found to have good test-retest repeatability. Children with OM histories had poorer EHF hearing than children without OM histories. The EHF hearing in OM children appeared to be related to OM severity. Children with residual tympanometric abnormalities had poorer EHF hearing than OM children with normal middle ear function. The results suggest evidence for middle ear and inner ear components of EHF hearing losses in children with OM.

Developmental Changes in Multifrequency Tympanograms

The normal maturational course of tympanometric shape, static aural acoustic admittance and ear canal wall characteristics were investigated in healthy infants, who were followed at various time intervals in the first 4 months of life. Susceptance and conductance tympanograms were recorded from both ears of each subject at four probe frequencies or more. In addition, quantitative pneumatic otoscopy was performed utilizing air pressure changes of the same magnitude as those typically used in tympanometry. Results for the group were an increase in admittance magnitude with increasing age at frequencies above 226 Hz. Admittance phase angle increased with age at all frequencies, indicating a growing contribution of compliant elements in the first 4 months of life. The course of development of input admittance at the tympanic membrane differed among individual infants. Otoscopic findings indicated that external ear canal differences cannot completely account for tympanometric differences between young infants and adults.

Screening Tympanometry: Criteria for Medical Referral

Tympanograms were obtained from normal preschool and adult subjects with a prototype hand-held tympanometer to obtain normative values for four tympanometric variables: static admittance, equivalent ear canal volume, tympanometric peak pressure, and gradient. Effects of age group, sex, and pump speed (200 or 400 daPa/s) were determined. The results were incorporated into a four-part screening protocol (history, visual inspection, audiometry, and tympanometry) designed to reduce the excessive error rates associated with screening strategies that rely exclusively on tympanometry.

High frequency hearing loss associated with otitis media.

Objective: Long‐term effects of otitis media (OM) on hearing in both conventional and high frequency (HF) regions in children were studied. Design: Children with OM were enrolled in a prospective study of sequelae after tympanostomy tube insertion (intubation) and were examined serially at 6‐mo intervals with audiometry and multifrequency tympanometry, and every 3 mo with tympanometry and otoscopy for at least 3, and up to 5 yr. Hearing thresholds in conventional and HF regions were compared with those of an age‐matched control group of children who had 2 or fewer documented episodes of any type of OM since birth. Frequency of OM during follow‐up, number of intubations, use of ototopical eardrops, age, and sex along with several other factors were analyzed for a relationship to HF hearing loss. Results: Otitis media history was associated with poorer HF hearing, but the presence of subtle residual middle ear dysfunction was not associated with an additional effect on HF hearing. Active middle ear disease significantly affected both conventional and HF thresholds. The number of intubations and frequency of OM during follow‐up were significantly and positively associated with poorer HF thresholds. Several other factors, including middle ear appearance at intubation, presence of tympanosclerosis, age, male gender, and use of ototopical eardrops, were also associated with poorer HF hearing but failed to reach significance after their intercorrelation with number of intubations and frequency of OM was considered. Conclusions: High frequency hearing loss was associated with OM after middle ear disease resolved and after middle ear dysfunction was excluded. Relatively poorer HF hearing thresholds found for older children with OM histories appeared to be attributable to time spent with ear disease. Children at greatest risk for HF hearing loss were those who required multiple intubations. Older children tended to have poorer hearing in both conventional and HF regions, suggesting that the effects of OM on hearing thresholds may be progressive.

Multifrequency Tympanometry: Current Clinical Application

Multifrequency tympanometry has emerged as a clinically feasible test with the advent of computer-controlled systems that can store and analyze complex immittance components at multiple probe tone frequencies. The theoretical basis for understanding multifrequency tympanometry has existed for years, but the diagnostic utility of data obtained at frequencies higher than 660 Hz needs further clarification. In this short course, the Vanhuyse model for the analysis of multifrequency tympanograms is discussed and clinical examples illustrating the usefulness of the model are presented. Normative data are provided for adults and children, and various methods for data acquisition and measurement of resonant frequency are presented.

Hearing Screening in the Newborn Intensive Care Nursery: Comparison of Methods:

Patients in the neonatal intensive care unit were tested by hearing screening tests including auditory brain stem response (ABR), transient and distortion-product otoacoustic emissions (TEOAEs and DPOAEs), and acoustic stapedius reflex (ASR), and by middle ear function tests including multifrequency tympanometry and pneumatic otoscopy. Pass rates on hearing tests were 75% to 89%. TEOAEs produced the lowest pass rate, and DPOAEs the highest. TEOAE, DPOAE, or ASR testing followed by ABR testing of initial failures produced pass rates of about 90%. The most efficient combination was DPOAEs followed by ABR. Pass rates tended to decrease with age. Of patients who failed 226-Hz and 678-Hz tympanometry, 30% to 67% passed hearing tests, suggesting a high false-positive rate for these immittance tests. The 3 ears that failed the 1000-Hz tympanogram failed all hearing tests. Many ears were abnormal by pneumatic otoscopy but passed hearing tests, suggesting that the usual ear examination criteria may not apply to infants.

Effect of ear‐canal air pressure on evoked otoacoustic emissions

The effect of ear-canal air pressure on click-evoked otoacoustic emissions was measured for pressures ranging from 200 to -200 daPa and stimulus levels ranging from 60-90 dB PeSPL. Positive and negative ear-canal pressures (relative to ambient pressure) reduced the emission amplitude by 3-6 dB. A spectral analysis of the emissions revealed that the effect of ear-canal air pressure is that of a high-pass filter with a cutoff frequency of 2600 Hz and a slope of 4 dB/oct. The spectral changes are the expected effect of an increase in stiffness of the middle ear and were independent of pressure polarity and click level. Ear-canal air pressure substantially reduced the reproducibility of the emission waveform, in many cases rendering the emission indistinguishable from background noise. The implication of these findings for hearing screening applications is that a high false alarm rate may occur in normal-hearing patients with intratympanic air pressures that are significantly different from ambient pressure.

Multifrequency tympanometry in normal adults

Abstract Multifrequency tympanograms were recorded from 56 ears of 28 normahearing adult subjects to obtain normative data and to determine abnormal criteria for tympanometric measures. Static admittance, tympanometric width, and tympanometric peak pressure at 226 Hz were analyzed along with eight different estimates of the resonant frequency of the middle ear. Based on testretest reliability and normal distribution characteristics, preferred methods for clinical estimation of resonant frequency were determined. The sweep pressure mode [ear canal pressure is swept while probe frequency is held constant) is preferred for detection of abnormally high resonant frequencies. The sweep frequency mode (probe frequency is swept while ear canal air pressure is held constant] is preferred for identification of abnormally low resonant frequencies. Compensation for ear canal volume at +200 daPa was preferred over other compensation methods for estimation of middle ear resonant frequency.

The Effect of Middle Ear Pressure on Transient Evoked Otoacoustic Emissions

Abstract To determine the effect of middle ear pressure on transient evoked otoacoustic emissions (TEOAEs), emissions were recorded in ears with tympanometric peak pressures 1-100 daPa and audiometric thresholds 1 30 dB HL at 500 through 2000 Hz. TEOAEs were alternately recorded at ambient pressure and at the tympanometric peak pressure. As demonstrated for the 14 ears tested, equalization of the middle ear pressure increased TEOAE amplitude. Reproducibility was similarly improved in 12 of 14 ears. Unequalized middle ear pressure attenuated low frequency emissions more than high frequency emissions. These amplitude and spectrum differences were consistent with previously reported observations of the effects of ear canal pressure on otoacoustic emissions. Results suggest that unequalized middle ear pressure may increase the occurrence of false positive failures, if otoacoustic emission testing is used for hearing screenings without consideration of middle ear pressure.

High-frequency hearing loss and wideband middle ear impedance in children with otitis media histories.

Objective: This study was undertaken to determine the relationship between extended‐high‐frequency (EHF) hearing losses and wideband middle ear impedance in children with chronic otitis media (OM) histories. Design: Children with OM histories were selected from a prospective study cohort if they had normal tympanograms, no air‐bone gaps, and no otoscopic evidence of active OM at the time of testing. OM subjects were divided into two groups, those with Better Hearing in the EHF range and those with Worse Hearing in the EHF range. The OM groups were compared with an age‐matched, healthy Control group that had no more than five documented episodes of OM and no more than two in any 1 yr. All children were 9 to 16 yr of age. Subjects were tested by standard audiometric methods in the conventional audiometric range (0.25 to 8.0 kHz) and the EHF range (8 to 20 kHz). Middle ear impedance and reflectance were measured with an experimental system over the frequency range 0.25 to 10.08 kHz. Results: The Worse Hearing OM group had slightly poorer hearing in the conventional audiometric frequency range compared with the other two groups. The Better Hearing OM group and the Control group had nearly identical EHF hearing. The Worse Hearing OM group had significantly poorer EHF hearing compared with the other two groups, the difference increasing exponentially with frequency. Middle ear impedance differences among groups were confined to low frequencies (<2 kHz). The Control group had significantly higher negative reactance than the two OM groups. There were no significant group differences in impedance or reflectance in the high frequencies (2 to 10 kHz). Conclusions: The results of this study confirm those of previous reports that children who have recovered from chronic OM have significantly poorer hearing in the EHF range compared with children without significant OM histories. The EHF hearing losses that occur in children with OM histories are strongly frequency dependent, suggesting a preferential effect on the base of the cochlea. Middle ear impedance and reflectance differences do not account for the EHF hearing losses observed in children with OM histories. The results support the hypothesis that OM‐related EHF hearing losses are cochlear in origin.