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Biomedical subjects

S Silman

Publications and source records attributed to S Silman.

At least 37 records · Page 2Linked to original sources
PubMed1989

Contralateral acoustic-reflex growth function in a patient with a cerebellar tumor: a case study.

The contralateral acoustic-reflex growth functions (ARGFs) for 500-Hz and 1000-Hz tonal activators were obtained pre- and postsurgery in a patient with a right cerebellar tumor. The acoustic-reflex magnitude was quantified as the change in equivalent air volume at the tympanic membrane during acoustic-reflex contraction. The presurgical ARGFs were shallow in the right ear and steep in the left ear at both activator frequencies. The postsurgical ARGFs were steep, bilaterally, reflecting a return to normal in the right ear. The implications with respect to the use of the ARGF measure in differential diagnosis are discussed.

Carcinoma, Squamous Cell↗
PubMed1989

Some effects of signal bandwidth and spectral density on the acoustic-reflex threshold in the elderly.

The acoustic-reflex thresholds (ART) for multicomponent tonal complexes of varying bandwidth and spectral density were obtained from 20 normal-hearing (air-conduction thresholds less than or equal to 20 dB HL at 250-8000 Hz) young adults ranging in age from 20-30 years and 20 normal-hearing, old subjects ranging in age from 60-71 years. The results revealed that the ART decreased with spectral density, plateauing after seven components in the young group and after five components in the old group; the decrease in the acoustic-reflex threshold as a result of the increase in spectral density was less in the old than in the young group. The bandwidth effect (when bandwidth was plotted in hertz or octaves) on the acoustic-reflex threshold was present in the young adults, but substantially reduced in the elderly, as evidenced by the statistically significant interaction between subject group and signal bandwidth. The spectral density results are discussed in terms of their theoretic implications for the energy summation capacity and frequency resolution of the auditory system. The bandwidth results are discussed in terms of their theoretic implications for the frequency-resolving power of the auditory system.

Acoustic Stimulation↗
PubMed1989

Effect of direction of pressure change on obtaining airtight seals in tympanometry.

To determine the effect of change in pressure direction on obtaining a seal during tympanometry, an ascending approach (-/+) was attempted when the traditional, descending approach (+/-) was unsuccessful in maintaining an airtight seal. Results revealed that a seal was achieved using the ascending direction in twelve ears when the descending method failed; in only four ears, neither method was successful.

Acoustic Impedance Tests↗
PubMed1988

Ipsilateral acoustic-reflex adaptation testing for detection of facial-nerve pathology: three case studies.

Abnormal acoustic-reflex adaptation monitored in the same ear for both contralaterally and ipsilaterally presented tonal activators is reported in three cases. One case had Bell's palsy, whereas the other two cases had no clinically observable evidence of seventh-nerve involvement. These cases show that the existence of abnormal acoustic-reflex adaptation in the absence of Bell's palsy does not necessarily implicate the presence of eighth-nerve pathology.

Acoustic Impedance Tests↗
PubMed1987

Long-term effects of monaural, binaural and no amplification in subjects with bilateral hearing loss.

This study expands upon our earlier work by comparing initial PB scores and audiometric thresholds with results obtained 4-17 years later for subjects with bilateral sensorineural hearing losses who were monaurally aided (n = 48), binaurally aided (n = 19), or unaided (n = 19). Thresholds decreased slightly for all groups, but aided and unaided ears did not differ significantly in this respect, revealing no acoustic trauma effect due to hearing aid use. PB scores decreased significantly only for the unaided ear of the monaurally aided subjects, but not for their aided ear, or for the binaurally aided or unaided groups. These findings suggest an auditory deprivation effect for the unaided ear of those wearing a monaural hearing aid. Changes in PB scores were not correlated with duration between the two test dates. Changes in PB scores were correlated with degree of hearing loss only for the unaided group.

Adult↗
PubMed1986

Prediction of hearing loss from acoustic-reflex thresholds in the older adult population.

The clinical applicability of prediction of hearing loss in 126 ears of 83 adults more than 44 years of age was investigated. The method of hearing-loss prediction was based on that proposed by Silman, Silverman, Showers, and Gelfand (J Speech Hear Res 1984;27:12-9). This method, which utilized the acoustic reflex thresholds for hearing-loss prediction, was modified to create a more clinically feasible procedure; 5 dB rather than 1 dB intensity increments and visual monitoring of needle deflection rather than the use of a graphic level recorder were used. This modified method yielded a high predictive accuracy for at least mild and/or high-frequency hearing impairment. Criteria based on acoustic-reflex threshold levels were developed to identify the presence of significant hearing loss (pure-tone average = or greater than 30 dB HL) in adults more than 44 years of age. The results have implications for hearing screenings for the difficult-to-test population such as the elderly.

Aged↗
PubMed1986

Consonant recognition in quiet and in noise with aging among normal hearing listeners.

Consonant recognition in quiet and in noise was investigated as a function of age for essentially normal hearing listeners 21-68 years old, using the nonsense syllable test (NST) [Resnick et al., J. Acoust. Soc. Am. Suppl. 1 58, S114 (1975)]. The subjects audited the materials in quiet and at S/N ratios of +10 and +5 dB at their most comfortable listening levels (MCLs). The MCLs approximated conversational speech levels and were not significantly different between the age groups. The effects of age group, S/N condition (quiet, S/N +10, S/N +5) and NST subsets, and the S/N condition X subset interaction were all significant. Interactions involving the age factor were nonsignificant. Confusion matrices were similar across age groups, including the directions of errors between the most frequently confused phonemes. Also, the older subjects experienced performance decrements on the same features that were least accurately recognized by the younger subjects. The findings suggest that essentially normal older persons listening in quiet and in noise experience decreased consonant recognition ability, but that the nature of their phoneme confusions is similar to that of younger individuals. Even though the older subjects met the same selection criteria as did younger ones, there was an expected shift upward in auditory thresholds with age within these limits. Sensitivity at 8000 Hz was correlated with NST scores in noise when controlling for age, but the correlation between performance in noise and age was nonsignificant when controlling for the 8000-Hz threshold. These associations seem to implicate the phenomena underlying the increased 8000-Hz thresholds in the speech recognition problems of the elderly, and appear to support the concept of peripheral auditory deterioration with aging even among those with essentially normal hearing.

Adult↗
PubMed1985

Consonant recognition in quiet as a function of aging among normal hearing subjects.

Consonant recognition in quiet using the Nonsense Syllable Test (NST) [Resnick et al., J. Acoust. Soc. Am. Suppl. 1 58, S114 (1975)] was investigated in 62 normal hearing subjects 20 to 65 years of age at their most comfortable listening levels (MCLs) and at 8 dB above and below MCL. Although overall consonant recognition performance was high (as expected for normal listeners), the effects of age decade, relative presentation level, and NST subsets were all significant, as was the interaction of age X level. The interactions of age X NST subset, and age X subset X level were nonsignificant. These findings suggest that consonant recognition decreases with normal aging, particularly below MCL. However, the relative perceptual difficulty of the seven subtests is the same across age groups. Confusion matrices were similar across levels and age groups. Percent information transmitted for several consonant features was calculated from the confusion matrices. Older subjects showed decrements in performance primarily for the features recognized relatively less accurately by the younger subjects. The results suggest that normal hearing older individuals listening in quiet have decreased consonant recognition ability, but that their confusions are similar to those of younger persons.

Adult↗
PubMed1984

Effect of age on prediction of hearing loss with the bivariate-plotting procedure.

The effect of age on accuracy of prediction of hearing impairment with the bivariate-plotting procedure was investigated in 72 normal-hearing subjects aged 20-69 years and in 86 sensorineural hearing-impaired subjects aged 20-83 years. The predictive accuracy with the bivariate-plotting procedure improved markedly when the data from subjects over 44 years of age were excluded from the bivariate plot. The predictive accuracy improved further when the construction of the line segments in the traditional bivariate plot was modified.

Adult↗
PubMed1984

Late-onset auditory deprivation: effects of monaural versus binaural hearing aids.

Performance on tests of pure-tone thresholds, speech-recognition thresholds, and speech-recognition scores for the two ears of each subject were evaluated in two groups of adults with bilateral hearing losses. One group was composed of individuals fitted with binaural hearing aids, and the other group included persons with monaural hearing aids. Performance prior to the use of hearing aids was compared to performance after 4-5 years of hearing aid use in order to determine whether the unaided ear would show effects of auditory deprivation. There were no differences over time for pure-tone thresholds or speech-recognition thresholds for both ears of both groups. Nevertheless, the results revealed that the speech-recognition difference scores of the binaurally fitted subjects remained stable over time whereas they increased for the monaurally fitted subjects. The findings reveal an auditory deprivation effect for the unfitted ears of the subjects with monaural hearing aids.

Audiometry, Pure-Tone↗
PubMed1983

Effects of hearing levels at the activator and other frequencies upon the expected levels of the acoustic reflex threshold.

Multiple linear regression equations were derived to define the expected levels of acoustic reflex thresholds (ARTs) at 500, 1000, and 2000 Hz predictable from hearing levels at 500-4000 Hz in 646 ears. When the hearing level at the activator frequency is less than or equal to 50 dB HL, ARTs tend to be best defined by a constant value of 86-90 dB HL with small adjustments due to the loss at the activator or higher frequencies. When the hearing level at the activator frequency is 55-90 dB HL, the ART is best predicted by a constant plus the degree of loss at that frequency plus the loss at 4000 Hz. These data present the clinician with empirically derived bases for determining the effects of other frequencies on a given ART. Application of these findings permits the clinician to apply known relationships in determining whether a particular ART is representative of those expected for normal and/or cochlear impaired ears, elevated or depressed, without having to rely on vague intuitions of such relationships. Clinical applications are discussed.

Acoustics↗
PubMed1983

The acoustic reflex threshold in aging ears.

This study investigates the controversy regarding the influence of age on the acoustic reflex threshold for broadband noise, 500-, 1000-, 2000-, and 4000-Hz activators between Jerger et al. [Mono. Contemp. Audiol. 1 (1978)] and Jerger [J. Acoust. Soc. Am. 66 (1979)] on the one hand and Silman [J. Acoust. Soc. Am. 66 (1979)] and others on the other. The acoustic reflex thresholds for broadband noise, 500-, 1000-, 2000-, and 4000-Hz activators were evaluated under two measurement conditions. Seventy-two normal-hearing ears were drawn from 72 subjects ranging in age from 20-69 years. The results revealed that age was correlated with the acoustic reflex threshold for BBN activator but not for any of the tonal activators; the correlation was stronger under the 1-dB than under the 5-dB measurement condition. Also, the mean acoustic reflex thresholds for broadband noise activator were essentially similar to those reported by Jerger et al. (1978) but differed from those obtained in this study under the 1-dB measurement condition.

Acoustic Stimulation↗
PubMed1982

Clinical application of the bivariate plotting procedure in the prediction of hearing loss.

This study examined the utility of the bivariate plotting approach to reflex-based hearing loss prediction, and introduced a modification to the method which accounts for the effects of mild and high frequency hearing losses. The effect of pure tone sensitivity at 3,000 Hz was found to be of particular importance in the predictive accuracy of the method. When 3,000 Hz is considered, the original concept of the bivariate graph can be further refined into three regions. Here, normal ears and those with substantial hearing loss can be identified with considerable success. A "grey area" between these correctly identifies some degree of loss with 89% accuracy.

Adult↗
PubMed1981

The relationship between magnitude of hearing loss and acoustic reflex threshold levels.

The acoustic reflex threshold (ART) was studied in 544 ears having hearing levels (ANSI-1969) ranging from 0 to 110 dB HL. The activating signals were pure tones (500, 1000, and 2000 Hz) presented at levels up to 125 dB HL. The results indicated that the ART increased with hearing loss beyond certain levels. The proportion of absence of reflex responses depends upon the degree of hearing loss, test frequency, and the limits imposed by the instrumentation. Absence of reflex responses is rare for hearing losses of less than about 80 dB HL when the hearing loss is attributable to cochlear involvement.

Acoustic Impedance Tests↗
PubMed1981

Effect of sensorineural hearing loss on the stapedius reflex growth function in the elderly.

The effect of sensorineural hearing loss upon stapedius reflex growth functions was studied in the elderly. The reflex activators were pure tones (500, 1000, and 2000 Hz) and broadband noise; reflex magnitude was expressed in decibels relative to static acoustic impedance. When expressed in decibels relative to reflex threshold, the mean growth functions of the elderly were reduced compared to previous data for young subjects [Silman, Popelka, and Gelfand, J. Acoust. Soc. Am. 64, 1406--1411 (1978)] and the noise functions differed in terms of both shape and magnitude. When expressed in SPL, the mean growth functions of the normal hearing elderly demonstrated saturation at high activator levels, whereas saturation was not observed in the mean growth functions of the hearing loss subjects. In the normal elderly, saturation was found to be frequency dependent. The saturation effect is discussed in terms of energy integration of the reflex response in the aging ear.

Acoustic Stimulation↗
PubMed1979

Prediction of hearing levels from acoustic reflex thresholds in persons with high-frequency hearing losses.

This study examined the precision of the bivariate method in subjects with high-frequency sensorineural hearing loss. The current bivariate data effectively separated normal hearing subjects from those with pure tone averages of greater than 32 dB HL, in a manner consistent with the results of Popelka and Trumpf (1976) and Margolis and Fox (1977b). However, for persons with high-frequency losses the prediction of hearing levels from acoustic reflex thresholds (ARTs) appears to be complicated. Moderate hearing losses involving 500, 1000 and 2000 Hz ("speech frequencies") as well as higher frequencies were identified on the basis of elevated average ARTs for 500, 1000 and 2000 Hz. Normal ears (pure tone averages of less than 30 dB HL) were isolated from others on the basis of position on the bivariate graph. Those with (1) normal hearing in the "speech frequencies" and a high-frequency loss and (2) a mild loss in the "speech frequencies" and a high-frequency loss, could be separated from those with normal hearing by location on the bivariate graph, and from those with moderate (or worse) losses on the basis of average ART for tones. Consideration of these findings is useful in the evaluation of patients at risk for high-frequency loss, such as patients with noise exposure, and is particularly useful in cases of suspected functional impairment within this population. A modification of the bivariate method is suggested which extends its application to patient populations with a large incidence of high frequency sensorineural hearing loss.

Adult↗