Acoustic-Immittance Measures in Normal Ears

1987 ◽  
Vol 30 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Terry L. Wiley ◽  
Dana L. Oviatt ◽  
Michael G. Block

A data base of acoustic-immittance measures in normal adults is presented. The subject pool consisted of 127 adults with normal hearing and a negative otologic history. Norms are presented for hearing thresholds, ipsilateral and contralateral acoustic-reflex thresholds, tympanometry, static acoustic-admittance measures, and middle-ear (tympanogram peak) pressure.

1980 ◽  
Vol 23 (2) ◽  
pp. 405-418 ◽  
Author(s):  
David J. Thompson ◽  
John A. Sills ◽  
Kay S. Recke ◽  
Duc M. Bui

Growth in amplitude of the acoustic reflex to filtered noise and tones of 500, 1000, and 2000 Hz was measured with an aural acoustic-admittance meter in 30 persons between the ages of 20 and 79 years. Although thresholds of the acoustic reflex did not vary significantly across the age range of the subject sample, the rate of growth in amplitude decreased linearly with increase in age decade. Given information on the aging of structures in the acoustic reflex pathway, the growth data are interpreted tentatively to mean that the contractual capacity of the stapedius muscle is diminished in older ears.


1987 ◽  
Vol 30 (2) ◽  
pp. 207-214 ◽  
Author(s):  
Catherine L. Riedel ◽  
Terry L. Wiley ◽  
Michael G. Block

The purpose of this study was to develop instructions and procedures and to establish a normal data base for four tympanometric tests of Eustachian tube function: Valsalva, Toynbee, Inflation, and Deflation. Data were obtained for 24 young adults (48 ears) with normal hearing and normal middle-ear function. The tympanograms were analyzed for differences between baseline and experimental (postmaneuver) and baseline and posttest tracings for seven measures: tympanogram peak pressure, peak acoustic admittance, static acoustic admittance, negative gradient, positive gradient, and negative and positive acoustic-admittance values at ±400 daPa. The results indicated a statistically significant difference only in peak pressure for baseline and experimental tympanograms. Peak-pressure shifts were most pronounced for the Valsalva and Toynbee procedures. The small pressure shifts characteristic of the Inflation and Deflation procedures coupled with the potential for instrumental error severely limit the use of these procedures as means of obtaining reliable indices of tubal function.


1984 ◽  
Vol 27 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Richard H. Wilson ◽  
Janet E. Shanks ◽  
Susan K. Kaplan

The influence that repeated tympanometric trials have on the aural-acoustic admittance characteristics of the middle-ear transmission system was studied in 24 young adults. The 226-Hz and 678-Hz data were generated by concurrently digitizing the conductance and admittance tympanograms at 25 daPa/s for both ascending and descending pressure directions. Ten successive trials for each frequency and direction of pressure change were made. Changes in admittance corrected for ear canal volume across the 10 tympanometrie trials were computed. The results demonstrated that generally admittance increases as the number of trials increases. For many subjects, the complexity of the tympanometric configuration also increases across trials. The results from eight subjects with single-peaked 678-Hz tympanograms were compared with the results from eight subjects with notched 678-Hz tympanograms to explain the mean decrease in susceptance across tympanometric trials. Finally, the pressure peak locations of the conductance, susceptance, and admittance tympanograms were evaluated and are discussed. The effects that differences in peak pressure location have on the computed static admittance values are presented.


1974 ◽  
Vol 17 (3) ◽  
pp. 526-530 ◽  
Author(s):  
Frederick N. Martin ◽  
Sherry Coombes

Twenty normal-hearing individuals served as subjects in an experiment designed to determine the relationships between positive and negative air pressure in the external auditory canal and the intensity required to elicit the acoustic reflex. Pressure was varied from +240 to −240 mm H 2 O. Changes in the magnitude of acoustic impedance were measured on an acoustic impedance meter and displayed graphically on a Y-T recorder. As air pressure was varied in the canal and the tympanic membrane was displaced from its position of greatest compliance, systematic increases in the intensity required to elicit the reflexes were noted. The magnitude of the differences was smaller than might have been anticipated, not exceeding a mean of 5.1 dB at −240 mm H 2 O.


2005 ◽  
Vol 119 (6) ◽  
pp. 489-491 ◽  
Author(s):  
G D Howsam ◽  
A Sharma ◽  
S P Lambden ◽  
J Fitzgerald ◽  
P R Prinsley

Subjective tinnitus (heard only by the patient) is a common otological complaint. Objective tinnitus (heard by the examiner as well as the patient) is extremely rare. There are only a few cases of objective tinnitus, secondary to middle-ear myoclonus, described in the literature.We present the case of a child with bilateral, congenital, objective tinnitus, secondary to middle-ear myoclonus, with otherwise normal hearing thresholds (250Hz-8kHz), and with no evidence of intra-cerebral or systemic disorders. No similar case has been reported in the world literature.


1965 ◽  
Vol 8 (3) ◽  
pp. 213-222 ◽  
Author(s):  
Alan S. Feldman ◽  
Jozef Zwislocki

Seventeen ears of 12 subjects with normal hearing were tested in both a laboratory and a clinical setting to study impedance changes in normal human ears associated with the acoustic reflex. Compliance and resistance at the eardrum were measured with middle ear muscles relaxed and contracted by means of a contralateral noise stimulus, respectively. The reflex induced impedance changes were compared to similar impedance data obtained by other investigators, and to typical otosclerotic impedance values. The reflex is shown to affect the impedance by a decrease in compliance and a slight decrease in resistance.


Author(s):  
Andrew Stuart ◽  
Emma K. Tomaszewski ◽  
Baylee M. Engelhardt

Abstract Background During audiologic evaluations, an examination of interaural asymmetry is commonly evaluated. To date, however, interaural differences for tympanometric indices have not been reported for adults. Without documented tympanometric right-left differences, one cannot determine if asymmetries are normal or are indicative of significant clinical asymmetries. Purpose The purpose of this study was to investigate interaural asymmetries in peak compensated static acoustic admittance (Ytm), equivalent ear canal volume (Vea), tympanometric peak pressure (TPP), and tympanometric width (TW) in normal adults. Research Design Descriptive, correlational, and inferential measures designs were employed. Study Sample Participants were 188 otologically normal Caucasian young adults (i.e., 77 females and 111 males; M = 23.0 years, standard deviation [SD] = 2.7, range = 18–30 years). Data Collection and Analyses Ytm, Vea, TPP, and TW measures were obtained bilaterally from an admittance tympanogram using a 226 Hz probe tone. Separate two-factor mixed measures analysis of variance examined the effect of ear and sex for each tympanometric index. Correlation analyses examined the association between right and left ear indices. Interaural differences in tympanometric indices were examined with independent t-tests. Critical differences, for deciding if two tympanometric indices are different between ears, were computed from the standard deviations of the right–left ear difference for statistical confidence levels of 85, 90, 95, and 99%. Results The effect of ear was not statistically significant (p > 0.05) on any tympanometric index. Females had significantly lower Ytm and smaller Vea measures than males (p < 0.05). Correlations between all right and left tympanometric indices were positive and statistically significant (p < 0.05). There were no statistically significant differences in interaural differences for any of the tympanometric indices as a function of sex (p > 0.05). Critical differences, for confidence levels for 85% to 99% confidence ranged from ± 0.20–0.36 mmhos for Ytm, ± 0.23–0.41 cm3 for Vea, ± 11.1–19.8 daPa for TPP, and ± 27.2–48.7 daPa for TW. Conclusion A clinician can use these critical differences to determine if tympanometric index interaural differences in ears of young normal Caucasian adults are statistically significant.


1991 ◽  
Vol 34 (5) ◽  
pp. 1197-1206 ◽  
Author(s):  
Terry L. Wiley ◽  
Kathryn A. Barrett

Test-retest reliability for tympanometric measures was evaluated across five sessions in 20 subjects with normal hearing and normal middle-ear function. Tympanograms were obtained on each ear for probe frequencies of 226, 678, and 1000 Hz using both ascending and descending directions of pressure change. Across all conditions, the tympanometric measure that consistently demonstrated the highest test-retest reliability was compensated static acoustic admittance. Test-retest correlations for peak compensated static acoustic admittance measures were higher than those for ambient measures across all probe frequencies and both directions of pressure change; the differences in correlations for peak and ambient measures, however, reached significance only for 226-Hz conditions. Across-session correlations for tympanogram width did not differ significantly for measures referenced to the lowest tympanogram tail and those referenced to +200 daPa.


1978 ◽  
Vol 21 (2) ◽  
pp. 295-308
Author(s):  
Terry L. Wiley ◽  
Raymond S. Karlovich

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.


2014 ◽  
Vol 129 (3) ◽  
pp. 1449-1499 ◽  
Author(s):  
José Luis Montiel Olea ◽  
Tomasz Strzalecki

Abstract This article provides an axiomatic characterization of quasi-hyperbolic discounting and a more general class of semi-hyperbolic preferences. We impose consistency restrictions directly on the intertemporal trade-offs by relying on what we call “annuity compensations.” Our axiomatization leads naturally to an experimental design that disentangles discounting from the elasticity of intertemporal substitution. In a pilot experiment we use the partial identification approach to estimate bounds for the distributions of discount factors in the subject pool. Consistent with previous studies, we find evidence for both present and future bias.


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