Biomedical subjects

S A Gelfand

Publications and source records attributed to S A Gelfand.

At least 19 recordsLinked to original sources

PubMed1998

Optimizing the reliability of speech recognition scores.

Speech recognition assessment involves a dilemma because clinicians want a test that is short and reliable, but statistical principles dictate that a short test is unreliable. Curves representing the variability of test scores based on the binomial model reveal that approximately 450 scorable items are needed in order to optimize the reliability of a speech recognition test. A testing approach was developed to achieve this sample size while retaining the principal features of the most commonly accepted speech recognition tests (i.e., monosyllabic words presented in an open-set format, verbal responses, and right/wrong scoring). It involves the use of an interactive computer program to present CNC words in 50 three-word groups, which are scored phonemically, resulting in 450 scorable items. Normal performance is described as a function of both presentation level and signal-to-noise ratio. Comparisons of test and retest scores for 100 individuals with normal hearing and 100 persons with sensorineural losses revealed that the approach achieves the degree of reliability predicted by the binomial model for both groups. Phoneme scores accounted for 99% of the variance of word scores for most of the performance range encountered in clinical practice, making it possible for test outcomes based on phonemic scoring to be expressed in terms of equivalent word recognition scores.

Adult↗

PubMed1995

Long-term recovery and no recovery from the auditory deprivation effect with binaural amplification: six cases.

Six subjects who developed individually significant auditory deprivation effects associated with monaural amplification were tracked for 6.2 to 15.1 years from the time of their initial hearing aid fitting. Each subject received binaural hearing aids after the auditory deprivation effect became apparent and used binaural amplification for at least 4 years. The findings corroborate and expand upon existing case reports. Several general configurations of recovery and no recovery following the introduction of binaural amplification were identified: (1) cases in which auditory deprivation effects developed within about 2 years and recovered completely within about 2 years of binaural use; (2) cases with significant but incomplete recovery; and (3) cases in which the auditory deprivation effect took several years to develop and did not recover following several years of binaural amplification. Clinical implications of the results are proposed.

Adult↗

PubMed1994

Acoustic reflex threshold tenth percentiles and functional hearing impairment.

This study addressed the issue of whether functional impairments can be identified or confirmed using tonal acoustic reflex thresholds (ARTs). Tonal ARTs from 74 ears with functional impairments were compared to 10th percentiles of the ARTs for normal and cochlear-impaired ears at 500 to 2000 Hz (Gelfand, Schwander, and Silman, 1990). Only one ear (5.3%) was correctly identified among the 19 ears in which all of the voluntary thresholds at 500 to 2000 Hz were < or = 55 dB HL. Acoustic reflex thresholds correctly identified functional losses in 70.9 percent, 78.6 percent, and 85.7 percent of the ears with voluntary thresholds > or = 60 dB HL at one, two, or three of these frequencies, respectively. The false positive rate was only 5 to 7 percent for a control group of 50 ears with genuine sensorineural hearing losses. The results indicate that tonal ARTs are an effective nonbehavioral tool for identifying or substantiating the presence of functional losses when thresholds are > or = 60 dB HL; however, ARTs cannot identify functional components when thresholds are < or = 55 dB HL.

Acoustic Stimulation↗

PubMed1993

Functional components and resolved thresholds in patients with unilateral nonorganic hearing loss.

This study expanded upon previous work (Gelfand & Silman, 1985) on the relationship between functional components (the difference between the nonorganic and resolved thresholds) and the underlying organic hearing levels. The nature of nonorganic hearing loss (NOHL) was studied with respect to hearing sensitivity after resolution of the nonorganic components in 25 patients with unilateral NOHLs. Most of the subjects had an organic hearing loss underlying the functional components. The configuration of the functional components as a function of frequency was related to that of the resolved hearing levels in a manner similar to that reported for bilateral NOHLs. The strategy employed to exaggerate the loss in the ear with the nonorganic overlay appeared to be unrelated to the nature of the loss in the opposite ear, but the perception of an interaural difference might in some way bias the patient to 'choose' a unilateral NOHL as opposed to a bilateral one. The findings confirm and expand upon the prior ones, suggesting the use of an internalized loudness-based anchor by patients with NOHLs. Thus, the pure tone configuration of NOHL is consistently accounted for on the basis of known and explainable auditory factors regardless of whether the hearing levels are exaggerated in one or both ears.

Adult↗

PubMed1993

Organic thresholds and functional components in experimentally simulated exaggerated hearing loss.

Previous studies on the relationship between functional overlays and underlying organic hearing levels in nonorganic hearing loss (NOHL) have relied upon the clinical resolution of the nonorganic portion of the loss. This study involved the first use of subjects with sensorineural losses in a simulated NOHL experiment. This is important because most adults with NOHLs have underlying sensorineural losses. Different configurations of the experimentally simulated functional components (the difference between the exaggerated and real thresholds) as a function of frequency were associated with (a) normal hearing; (b) losses becoming abruptly worse at 4000 Hz, and (c) sloping losses, respectively. Thus, the simulation data corroborate the observations made using clinical patients with resolved NOHLs, and provide further support for the notion that these patients typically employ a strategy involving the use of an internalized loudness-based anchor on a within-ear basis to generate their exaggerated audiograms. Moreover, the outcome of this study reveals the limitations of restricting the subjects used in simulated NOHL experiments to normal hearing individuals, and highlights the importance of using hearing impaired groups in future experimental simulations of nonorganic hearing losses.

Adult↗

PubMed1993

Effects of prolonged lack of amplification on speech-recognition performance: preliminary findings.

The purposes of this investigation were two-fold: 1) to prospectively investigate the effect of prolonged lack of binaural amplification in the unaided ears of adults with bilaterally symmetrical sensorineural hearing impairment (BSSHI) fitted monaurally; and, 2) to prospectively investigate the effects of amplification on speech-recognition performance in the aided ears of monaurally and binaurally fitted subjects. Subjects consisted of 19 monaurally aided adults, 28 binaurally aided adults, and 19 control adults. Both ears of the experimental subjects (binaurally and monaurally aided adults) had BSSHI. The speech measures included the W-22 CID suprathreshold speech-recognition test, nonsense syllable test, and speech-perception-in-noise test. Initial testing was done between 6 and 12 weeks following hearing-aid fitting. Retests were performed approximately 1 year following the initial test. The results revealed that the mean aided minus unaided ear score for the nonsense syllable and W-22 tests increased significantly from the initial test to retest, reflecting a slight improvement in speech performance in the aided ear and a slightly greater decrement in the unaided ear. The findings were interpreted with respect to the theories of auditory deprivation and acclimatization.

Acclimatization↗

PubMed1993

Apparent auditory deprivation in children: implications of monaural versus binaural amplification.

This study investigated the effects of monaural versus binaural amplification upon the speech recognition scores (SRSs) of children with bilateral moderate sensorineural hearing loss after more than 4 years of hearing aid use. There was a significant decrease in SRSs for the unaided ears of the monaural hearing aid users, but there were no significant differences between initial and retest SRSs for their aided ears, or for both ears of those using binaural amplification. The SRS reduction was found to be large enough to be significant on an individual ear basis (by exceeding 95% confidence limits of the binomial model) in five of the ten unaided ears of the monaurally fitted children, but this did not occur for any of the initial-retest SRS differences in the aided ears of either group. These findings demonstrate that the auditory deprivation effect, which has been reported for adults using monaural hearing aids, is also found in children.

Acoustic Stimulation↗

PubMed1992

Speech recognition performance on a modified nonsense syllable test.

A modification of the City University of New York nonsense syllable test (CUNY NST) has been developed in which (a) the several subtests of the original test are replaced with a 22-item consonant-vowel (CV) subtest and a 16-item vowel-consonant (VC) subtest; and, (b) the response choices for each target syllable include all 22 initial and all 16 final consonants, respectively. In addition, the test tokens are presented as isolated syllables without a carrier phrase. These changes enable the resolution of confusions not possible on the original NST, and also the construction of a single confusion matrix each for CVs and VCs, respectively. The modified nonsense syllable test (MNST) provides results that compare favorably to those of the original NST.

Adult↗

PubMed1992

Adult-onset auditory deprivation.

Adult-onset auditory deprivation following prolonged lack of amplification in the unaided ears of persons with bilaterally symmetrical sensorineural hearing impairment was first reported in 1984. This article on the phenomenon includes a review of the literature on adult-onset auditory deprivation in relation to etiology, pathophysiology, hearing-loss manifestations, typical audiologic profile, amplification strategies, contraindications or challenges to conventional hearing-aid fitting, and future research. A case study illustrates the phenomenon of auditory deprivation from monaural amplification with recovery following binaural amplification. The results of a complete audiologic and acoustic-immittance evaluation are presented for a bilaterally sensorineural hearing-impaired male with adult-onset auditory deprivation who initially was fit monaurally and later was fit binaurally. A significant decrement in the suprathreshold word-recognition scores occurred only in the unaided ear following monaural amplification, illustrating the phenomenon of adult-onset auditory deprivation. Following binaural amplification, the suprathreshold word-recognition scores for the formerly unaided ear improved significantly, illustrating the phenomenon of recovery from the adult-onset auditory deprivation with binaural amplification.

Acoustic Stimulation↗

PubMed1990

Acoustic reflex thresholds in normal and cochlear-impaired ears: effects of no-response rates on 90th percentiles in a large sample.

Ninetieth percentile cutoffs for acoustic reflex thresholds (ARTs) were determined for a sample of 2,748 ears of 1,374 subjects with normal hearing and sensorineural loss of cochlear origin. All subjects had measurable hearing (less than or equal to 110 dB HL, ANSI-1969) at all three activator frequencies (500, 1000, and 2000 Hz). Cutoff values including "no responses" ("absent" reflexes at 125 dB HL) were higher than those excluding no responses when hearing losses were greater than about 55 dB. The 90th percentiles including the effects of no responses identified ears with retrocochlear involvement for hearing losses as great as about 756 dB. For greater hearing losses at the activator frequency, the no-response rate for both cochlear and retrocochlear cases is too high to enable them to be differentiated by acoustic reflex thresholds. The 90th percentiles are derived at each activator frequency collapsed across ears. It is therefore necessary to determine the probabilities that normal or cochlear-impaired ears will have one, two, or three frequencies at which the ARTs exceed their respective 90th percentiles. It was found that among normal and cochlear-impaired ears, 12.2% have one ART elevated above the 90th percentile, but only 5.6% have two or three elevated ARTs. Clinical implications are discussed.

Adult↗

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↗

PubMed1988

Sentence reception in noise from one versus two sources: effects of aging and hearing loss.

Sentence reception thresholds (SRTs) and babble detection thresholds (BDTs) were measured for signals presented from loudspeakers located at 0 deg and 90 deg azimuth. In addition, the S/B ratios necessary to achieve SRT in the presence of a 12-talker babble were determined under three conditions in which the speech and babble were presented from the same or spatially separated loudspeakers. In the first experiment, normal-hearing subjects were tested on two occasions. The results were highly reliable, with standard errors of the test-retest differences of less than 1dB for all conditions. In the second experiment, SRTs, BDTs, and S/B ratios were measured for three normal-hearing groups (less than or equal to 39, 40-54, and greater than or equal to 55 years) and for a fourth group with presbycusis (greater than or equal to 55 years). Presbycusics had higher SRTs and BDTs than all other groups regardless of age, and the oldest normals had higher thresholds than younger subjects. Presbycusics required higher S/B ratios than any of the normal groups, and the oldest normal group needed a higher S/B ratio compared to the youngest group. All groups demonstrated a significant advantage in S/B ratio when the sentences and babble sources were spatially separated compared to when they were presented from the same loudspeaker. There was no significant difference in the magnitude of advantage due to spatial separation of speech and noise between the normal groups regardless of age, but the presbycusics had significantly smaller advantages than all normals.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

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

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↗