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Biomedical subjects

J Jerger

Publications and source records attributed to J Jerger.

At least 91 records · Page 5Linked to original sources
PubMed1985

Accelerated hearing loss in urban emergency medical services firefighters.

A group of 192 firefighters serving in a busy urban emergency medical services (EMS) system was randomly selected for hearing tests. Total number of hours of siren noise exposure was calculated for each man and was compared to the outcome of hearing tests. Hearing loss was defined by the amount of sound intensity required to sense both midfrequency and high-frequency tones. Results indicated a correlation between hearing loss and the duration of siren noise exposure. The loss could not be attributed to non-job-related sources. In addition, the rate of hearing loss over time was 150% of that expected in age-matched, non-noise-exposed men. These findings confirm the observations of others that EMS personnel are at risk for hearing loss beyond that expected from aging alone, and they document that the hearing loss correlates with the duration of intense siren noise exposure.

Adult↗
PubMed1985

Patterns of phoneme identification error in cochlear and eighth-nerve disorders.

The purpose of this study was to determine whether patterns of phoneme identification error differ among listeners with cochlear and retrocochlear auditory disorder. Speech intelligibility performance was analyzed in 15 patients with confirmed eighth-nerve disorder and in 15 patients with cochlear disorders, matched to the retrocochlear group for age and audiometric configuration, using confusion matrices derived from responses to a monosyllabic word list. Results indicated that: (1) vowel errors were more prevalent in the retrocochlear group and varied directly with increasing stimulus presentation level; and (2) consonant errors did not differ in type or relative frequency between the two groups, nor was there a level-dependent effect for consonant errors. These results are supported by the results of closed-set vowel identification tests and thus do not appear to be an artifact of open-set testing. Vowel errors may account for a major part of the speech 'rollover' phenomenon typical of retrocochlear auditory dysfunction.

Adult↗
PubMed1984

Effect of peripheral hearing loss on the masking level difference.

The effects of both symmetric and asymmetric peripheral hearing loss on the masking level difference (MLD) at 500 Hz were studied in 651 subjects with conductive or sensorineural hearing loss and 270 normal controls. The data supported the hypothesis that the modification in MLD due to peripheral hearing loss results from deterioration in threshold in the antiphasic condition. These results provide correction factors for the normal MLD range as functions of boundary frequency of sensorineural loss above 500 Hz and degree of both symmetric and asymmetric sensitivity loss at 500 Hz in both subjects with conductive hearing loss and those with sensorineural hearing loss.

Adolescent↗
PubMed1983

Latency of the acoustic reflex in eighth-nerve tumor.

We evaluated acoustic reflex morphologic features in four subjects with confirmed, unilateral acoustic neuroma. All four subjects showed marked reduction in absolute reflex amplitude and alteration in the reflex amplitude-intensity function in the ear with the eighth-nerve disorder. The early, fast-rising component of the normal reflex was also typically absent in the ears with tumor. Interaural latency comparisons were made in three ways. At equal reflex sensation levels and equal reflex sound pressure levels, latency ws substantially delayed in the ear with the eighth-nerve disorder. At equivalent reflex amplitudes, however, latency was equivalent in normal ears and ears with eighth-nerve disorder. Results suggest that delayed onset of the acoustic reflex in subjects with eighth-nerve disorder may reflect amplitude and wave-form morphologic effects rather than a latency prolongation per se.

Adult↗
PubMed1983

Evaluation of diagnostic audiometric tests.

Five diagnostic audiometric procedures - acoustic reflexes, performance-intensity functions for monosyllabic (phonetically balanced) words, Békésy audiometry, Békésy comfortable loudness audiometry and suprathreshold adaptation test - were critically evaluated by decision matrix analysis and information theory analysis. The subjects were 20 patients with surgically confirmed eighth nerve disorders and 20 patients with presumed cochlear disorders. Each patient completed all test procedures. In terms of decision matrix analysis, sensitivity (correct identification of eighth nerve site) ranged from 45 to 85%. Specificity (correct rejection of patients with cochlear site) ranged from 70 to 100%. Predictive value ranged from 74 to 100% for positive results and from 62 to 82% for negative results. The efficiency of the five tests ranged from 68 to 78%. In terms of information theory, positive test results increased the probability of eighth nerve disorder in any subject from 50% (a priori) to 74-100%. Negative test results decreased the probability of eighth nerve disorder from 50% to 18-38%. Relative differences among the diagnostic effectiveness of the five individual test procedures were not pronounced. However, the suprathreshold adaptation test (results confined to 500, 1 000 and 2 000 Hz) was less efficient than the other four diagnostic techniques.

Adult↗
PubMed1983

Signal-averaging of the acoustic reflex: diagnostic applications of amplitude characteristics.

We employed simultaneous measurement of the crossed and uncrossed acoustic reflex (AR) and a signal-averaging technique to evaluate supra-threshold amplitude characteristics of the AR. By evaluating AR amplitude relationships in a mathematical model based on known afferent, efferent, and central pathway effects, we are able to compare results from a variety of patients and to make meaningful diagnostic interpretations.

Brain Stem↗
PubMed1982

Auditory brainstem response (ABR) to tone-pips: results in normal and hearing-impaired subjects.

We evaluated predictive accuracy of the auditory brainstem response (ABR) to tone-pip and click signals in normal and hearing-impaired subjects. Prediction of hearing sensitivity based on threshold of the ABR to tone-pips of 500 and 2 000 Hz to clicks was compared to the behavioral results obtained by conventional pure-tone audiometry. Results showed that error in prediction was greatest for the 500 Hz tone-pip and least for the click. In addition, predictive error for the 500 Hz tone-pip varied with the contour of the pure-tone audiogram. In general, greatest predictive error was observed in subjects with steeply sloping audiograms.

Acoustic Stimulation↗
PubMed1981

Pediatric speech intelligibility test. II. Effect of receptive language age and chronological age.

Performance for Pediatric Speech Intelligibility (PSI) Format I and Format II sentences was significantly different in children between the ages of 3 and 6 years. Performance differences were related to chronological age (CA) and receptive language (RL) ability. However, performance for Format I sentences in children with relatively low RL age and performance for Format II sentences in children with relatively high RL age were equivalent. This observation yielded an algorithm that determines the sentence format as a function of the child's RL age in order to yield 'language equivalent' norms for speech audiometry. Performance for PSI word materials was not influenced by differences in RL skill. CA developmental trends were noted for all speech materials.

Age Factors↗
PubMed1981

PB rollover and the acoustic reflex.

We present the results of a retrospective study of the speech understanding of 52 subjects with surgically confirmed acoustic neurinoma. Subjects were divided into three groups, depending on whether acoustic reflexes were all present, all absent, or present with abnormalities in the pathological ear. Results indicated that the three groups were homogeneous with respect to pure-tone sensitivity and PBmax. Subjects who lacked all acoustic reflexes, however, experienced significantly greater rollover of speech intelligibility at high intensities than did subjects with all or some reflexes intact. A neural-mechanical interaction is suggested as a basis for the rollover phenomenon in subjects with retrocochlear eight-nerve disorder.

Humans↗
PubMed1980

Speech, impedance, and auditory brainstem response audiometry in brainstem tumors. Importance of a multiple-test strategy.

Speech, impedance, and auditory brainstem response audiometric data were determined for four patients with intracranial tumor. Although the results of any individual measure may be ambiguous, consideration of the overall pattern of results on all three measures, in combination with audiometric sensitivity level, can lead to relatively precise site localization of brainstem auditory disorders.

Acoustic Impedance Tests↗
PubMed1980

The effect of degree of hearing loss on diagnostic test strategy: report of a case.

We discuss test results in a single case of eighth nerve disorder. The patient was evaluated twice, once when sensitivity loss was only mild and once when sensitivity loss was severe. Diagnostic contribution of individual test measures depended on degree of sensitivity loss. When the loss was only mild, the acoustic reflex test and auditory brain-stem response (ABR) audiometry were most sensitive to eighth nerve disorder. When sensitivity loss was severe, results of the acoustic reflex test and ABR audiometry became ambiguous. At that time, the more "traditional" audiometric test battery of Bekesy audiometry, suprathreshold adaptation test (STAT), and speech audiometry provided the most useful diagnostic information. Since degree of sensitivity loss at the time of initial evaluation is an uncontrollable variable, diagnostic strategy must include tests appropriate to a wide range of hearing loss.

Acoustic Impedance Tests↗
PubMed1980

Effects of age and sex on auditory brainstem response.

We examined amplitude and latency of the auditory brainstem response (ABR) waveform as functions of chronological age in 182 male and 137 female subjects. Hearing sensitivity was within normal limits in 98 subjects. The remaining 221 subjects had varying degrees of sensorineural hearing loss. Age had a slight effect on both latency and amplitude of wave V. In subjects with normal hearing, latency increased about 0.2 ms over the age range from 25 to 55 years. In the same group, wave V amplitude decreased about 10%. In subjects with sensorineural hearing loss, the latency increase was smaller, but the amplitude decrease was equivalent. Sex also affected the ABR. In both normal and hearing-impaired subjects, female subjects showed consistently shorter latency and larger amplitude at all age levels. Wave V latency was about 0.2 ms shorter and wave V amplitude was about 25% larger in female subjects.

Adult↗
PubMed1980

Pediatric speech intelligibility test. I. Generation of test materials.

Normal children between 3 and 7 years of age generated word and sentence messages for use in a new speech intelligibility test. Word materials did not differ as a function of chronological age, vocabulary skills, or receptive language ability. Sentence materials, however, did reflect differences in chronological age, vocabulary skills, and receptive language skills. Older children, approximately 5-10 years, responded with complete, adult-like sentences. Younger children, approximately 3-10 years, responded with either a proform substituted for the noun phrase subject of a sentence or by omitting the auxiliary verb "be" in forming the present progressive verb tense of the sentence. To represent the differences in the children's responses, two different types of test sentences were formed. In one construction, the test sentence is composed of (noun phrase/verb-ing/noun phrase), preceded by the carrier phrase "show me", e.g., "Show me a bear brushing his teeth". In the other construction, the test sentence is composed of (noun phrase/auxiliary verb-ing/noun phrase), e.g., "A bear is brushing his teeth". The two different sentence forms are proposed as a means of equating differences in normal language development among children.

Age Factors↗
PubMed1980

Normal audiometric findings.

We argue that the scope of basic audiometric assessment must be broadened to include speech audiometric measures sensitive to central auditory dysfunction. Findings in twenty cases of retrocochlear disorder illustrate the fact that conventional criteria of audiometric normalcy are inadequate.

Adolescent↗
PubMed1979

Low-frequency hearing loss in presbycusis. A central interpretation.

Elderly subjects with a central phonemically balanced (PB) and synthetic sentence identification (SSI) pattern show greater low-frequency (LF) sensitivity loss than elderly subjects with a peripheral PB-SSI pattern. This LF hearing loss is not the simple consequence of age, nor does the LF hearing loss account for depressed SSI performance. We conclude that LF sensitivity loss and a central PB-SSI pattern are both components of central aging. We discuss the implications for auditory rehabilitation of elderly subjects.

Aged↗