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At least 19 recordsLinked to original sources
PubMed1978

Acoustic neuroma: results of brain stem evoked response audiometry.

Brain stem evoked response (BER) audiometry presents abnormal findings in patients with acoustic neuromas. The test involves averaging of recordings at the vertex as sound-triggered nerve impulses travel from the cochlea to the brain stem. From the time the sound stimulus arrives at the cochlea until it reaches the first major brain stem synapse (within 10 milliseconds), five major waves have been identified as typical of normal averaged responses. Abnormality in the cochlea or eighth nerve causes specific changes in pattern, primarily in wave latency. These latency shifts can be used to predict the site of the lesion. In evaluating 17 lesions of the cerebellopontine angle, BER audiometry was accurate in the diagnosis of all of the tumors. This diagnostic tool should play a prominent role when acoustic tumor is suspected.

Adolescent↗
PubMed1976

Feasibility studies of evoked response audiometry in the mentally subnormal.

Evoked response audiometry was attempted on a group of seventy-seven unsedated severly subnormal patients up to the age of twenty-two years. Data of some clinical value were obtained in fifty-seven cases. It is suggested that sedation need only be used if the initial attempt at E.R.A. is unsuccessful. Over twenty per cent of the subjects appeared to have significant hearing loss.

Acoustic Stimulation↗
PubMed1979

Brain stem evoked response audiometry in a clinical practice.

Brain stem evoked response audiometry (BERA) is an effective method of evaluating the auditory pathway from the peripheral endorgan through the brain stem. The authors have found this test to be a valuable adjunct to the neurotologic evaluation and have applied the study to over 500 patients (639 ears) in a 22 month time span. BERA has an excellent success rate (98%) in determining the presence of cerebellopontine angle lesions and is helpful in establishing whether a hearing loss is of cochlear or retrocochlear type. The authors have found BERA of use in the diagnosis of multiple sclerosis as well as other neurologic diseases affecting the brain stem. It is a valid method of dealing with suspected malingerers and those who cannot respond to standard audiometric techniques. BERA has been helpful in determining the threshold of hearing in these patients. The authors conclude that BERA is a clinical study of practical significance and that more otolaryngologists should consider adding it to their diagnostic protocol.

Adolescent↗
PubMed1979

Brain stem evoked response audiometry in newborn hearing screening.

Brain stem evoked response audiometry (BERA) has been used as an auditory screening procedure in three groups of newborn infants. Group 1 consisted of 220 normal-term infants who were tested within 72 hours of birth; no hearing abnormalities were uncovered (386 ears), and their threshold responses (for clicks) lay between a 10- and 20-dB hearing level (re: adult). Group 2 consisted of 75 newborns who were treated in an intensive care unit for one to 14 weeks; four were found to have severe sensorineural hearing loss (seven ears) at the time of discharge. Group 3 consisted of a group of 325 infants, 1 year or older, who had previously been discharged from the same intensive care unit; of these infants, an additional four showed severe sensorineural hearing loss. All abnormalities that were identified by BERA were subsequently confirmed by conventional audiometric measures. The estimate of an incidence of severe hearing loss in one of 50 infants who required intensive care in the neonatal period calls for careful testing of this population.

Audiometry↗
PubMed1977

[Evoked response audiometry and vestibular examinations in patients with multiple sclerosis (author's transl)].

A possible involvement of the VIII cranial nerve in Multiple Sklerosis was investigated. 15 of the 135 MS-patients were tested by evoked response audiometry (ERA) and vestibular examinations. Only a central nystagmus, central vertigo and coordination disorder were seen. Lesions of the peripheral vestibular system and pathological data of the evoked response audiometry were not found.

Adult↗
PubMedDate not supplied

Reliability and validity of late vertex-evoked response audiometry.

In order to evaluate the current visual scoring technique in the late vertex-evoked response audiometry (ERA), the detectability of the response, errors in judgment, consistency between scorers and test-retest reliability were studied in adults and young children in waking and sleeping states. In waking adults, ERA proved to be a quite reliable and valid method for testing hearing objectively. On the contrary, a marked inconsistency was found in the appearance of the response in children during sleep. From a clinical standpoint, ERA in waking adults and sleeping children should be regarded as two substantially different methods.

Acoustic Stimulation↗
PubMed1975

Improving evoked response audiometry. Results of normative studies for machine scoring.

Normative studies were carried out with 8 adult subjects whose averaged evoked responses to auditory stimuli were scored visually and by a number of differently defined quantitative methods (machine scoring). In order to compare different scoring methods a common signal-to-noise ratio measure was introduced based on a model where noise is distributed normally and signal is additive. Visual and machine scoring proved to be approximately equally sensitive, but the latter lends itself to a superior testing procedure which takes only one-third as long for equivalent results and is not contaminated by subjective error. The authors believe that the greatest promise for improving evoked response audiometry lies in the exploration of the new techniques proposed earlier. Progress in proving out one of these techniques, fast periodic stimulation, is reported.

Acoustic Stimulation↗
PubMed1975

[Evoked response audiometry of the guinea pig before and after drop in hearing induced by furosemid (author's transl)].

Using particular surface electrodes evoked response audiometry (ERA) can be applied to small laboratory animals without any sedation or anaesthesia. In addition to other methods we have studied in this way the influence of extreme doses of Furosemid on the guinea pig inner ear. 6-20 mg Furosemid per 100 g of bodyweight (about 100 times the human therapy dose) were applicated i.v. within 5 min resulting in a drop of hearing immediately. For the anaesthesized animal the cochlear microphonic potentials (CM) decrease simultaneously, indicating Furosemid to act at the inner ear itself. By both methods recovery of inner ear function is seen to start about 10 min later according to the little biological half life of Furosemid. As being restricted in respect of time for the CM-measurements we are sure about reversibility only by the ERA-method.

Animals↗
PubMedDate not supplied

Intensity and frequency discrimination monitored by evoked response audiometry: clinical application.

Delta 1 and delta f repetitive stimuli superimposed on continuous 0.5-, 1- and 4-kHz carrier tones were administered to 20 normally hearing persons, 8 adults with sensorineural hearing loss, 10 adults with conductive hearing loss and 22 children subjected to evoked response audiometry (ERA) for assessment of hearing acuity. The intensity modulation depth ranged from + 1 to 10 dB. In the subjects with normal hearing and in the adult patients, three carrier tone levels were used whenever possible: 20, 40, and 60 dB SL. The frequency modulation depth ranged from -1 to -10% of the carrier tone frequency. The same levels for the carrier tone were used: 20, 40, and 60 dB SL. With a carrier tone level of 20 dB SL, a clear-cut vertex response was noted in 80% of the tests carried out in the normal adults with 5-dB delta i stimuli and with delta f stimuli of -3 to -5% in magnitude; the same figures are valid for the patients with sensorineural and conductive hearing loss. The patients with sensorineural hearing loss showed a tendency to give vertex responses with lower delta i stimuli than subjects with normal hearing. However, this difference was not statistically significant. According to our results, the children tested can be roughly divided into two groups, the first including subjects with responses to delta i stimuli of +5 and +10 dB and delta f stimuli of -5% and -10%; the second group including subjects with no clear-cut responses to these stimuli.

Acoustic Stimulation↗
PubMed1975

[Basis and clinical application of the "contingent negative variation" in "evoked response audiometry" (author's transl)].

After repeated stimulation with an indicative stimulus and a second imperative stimulus, a slow negative potential shife, the "Contingent Negative Variation" (CNV), can be recorded in the EEG before the second stimulus. On account of the main features of CNV two qualitative tests can be used in audiometry. "Tone-CNV" is an objective test of perception of a pure-tone. The indicative pure-tone is followed regularly by a second imperative stimulus, a flash of light or a slide. The appearance of CNV is the positive sign of perception, even if the "acoustically evoked potential" (AEP) is difficult to define. Adults and children (5 to 12 years) with normal hearing or suffering from several forms of hearing loss developed a CNV, except those patients with severe brain damage. The advantage of this method is the short testing time and accentuation of AEPs. The test can be also done under sedation. In "Objective Speech Audiometry", a proof of concept discrimination, only words of one concept are combined with a second imperative stimulus. The other group of words of the second concept remains "unreinforced". After correct discrimination all normal subjects developed a CNV before the second stimulus and after the "unreinforced" concept a "Discriminative Positive Variation" (DPV). Thus, this method can be used for clinical purposes. Loss of discrimination, perseveration phenomena and hemispheric differences were observed in aphasic patients.

Acoustic Stimulation↗