Analysis of the efficiency of retrocochlear screening.

The auditory brainstem response (ABR), as well as associated audiologic and radiographic studies of 175 patients suspected of having cerebellopontine angle tumors were reviewed. The majority of patients presented with asymmetric hearing loss. Eight acoustic neuromas were identified. All eight had abnormal ABRs. The false-positive rate was 22%. Rollover and acoustic reflex testing played a minimal role in the decision as to whether or not an ABR was ordered and, as a result, are not important in the search for retrocochlear disease. The cost per tumor diagnosed was roughly $7600. A rational approach to tumor screening based on the efficiency and cost of the screening tests, the frequency of abnormal ABRs, and the cost per tumor diagnosed is presented.

Stimulus repetition rate effect on the auditory brainstem response in systemic lupus erythematosus.

Neuropsychiatric involvement is common in systemic lupus erythematosus (SLE), but, in early half of cases, indications are not present on examination. Auditory brainstem response (ABR) measures using differential stimulus repetition rates have been reported as sensitive indicators of subclinical central nervous system (CNS) disorders associated with SLE. In the present study, ABRs were measured in a group of normal-hearing subjects with SLE, as well as in a group of subject controls. Differences in interpeak latency (IPL) measures obtained using low- and high-stimulus repetition rates did not reach statistical significance (P greater than .05). Clinical utility of ABRs using high- and low-stimulus repetition rates for the identification of occult CNS disorder in patients with SLE was not demonstrated.

Repair of mandibular fractures: plating vs. traditional techniques.

The treatment of mandibular fractures is a challenge for the otorhinolaryngologist-head and neck surgeon. Recent technologic advances have resulted in the development of rigid fixation techniques that hold promise for the early and optimal restoration of mandibular structure and function. The purpose of this article is to review the dental and orthopedic principles used in our mandibular fracture management, describe compression plating methodology, and discuss optimal techniques for its use. Results using rigid fixation procedures were compared with those using a variety of more traditional techniques in a retrospective analysis of 57 cases. The advantages, limitations, and indications for use of plating technology are discussed, and prevention of complications is emphasized.

Insert earphones for audiometry: applications, advantages, and limitations.

The measurement of hearing sensitivity during audiometry requires precise presentation of auditory stimuli. In most cases, these stimuli are introduced to the listener via standard earphones. Technical problems associated with these earphones have troubled clinicians for years. An alternative earphone system for audiometry was introduced that uses shoulder-worn transducers with inserts for connection with the external auditory canal. Although insert earphones are not intended to supplant standard earphones, experimental evidence and clinical observations support the advantageousness of these earphones under a variety of clinical conditions.

Clinical applicability of insert earphones for audiometry.

Insert transducers for audiometry are available which may offer significant advantages over older 'standard' headphones. Clinicians have remained cautious in using such devices due to the paucity of experimental data demonstrating their comparability with more widely used devices. The purpose of this investigation was to compare and contrast pure-tone audiometric thresholds obtained using insert earphones with those measured utilizing conventional supra-aural transducers in normal and hearing-impaired subjects. A second purpose was to examine the differential effects on the hearing threshold level of two coupling systems for the insert device. There were no clinically significant differences among pure-tone thresholds measured with the three earphone/coupler arrangements for subjects with normal and impaired hearing. Advantages and limitations of insert earphones are discussed.

Electromyographic biofeedback for treatment of tinnitus.

Electromyographic (EMG) feedback procedures were utilized in treating two adult patients with idiopathic subjective tinnitus. The relationship between behavioral severity ratings of tinnitus and EMG activity at the frontalis muscle was investigated using a single-subject, double-reversal experimental design. Biofeedback procedures were effective in modifying EMG activity levels, but changes in EMG levels were not related systematically to behavioral ratings of tinnitus. It was concluded that the physiologic effects of EMG biofeedback procedures may not be the active ingredient in such treatment procedures.

Modeling HTL of industrial workers using multiple regression and path analytic techniques.

This study compared path analytic with multiple regression analyses of hearing threshold levels (HTLs) on 258 adult textile workers evenly divided into low- and high-noise exposure groups. Demographic variables common in HTL studies were examined, with the addition of iris color, as well as selected two-way interactions. Variables of interest were similarly distributed in both groups. The results indicated that (1) different statistical procedures can lead to different conclusions even with the same HTL data for the same Ss; (2) conflicting conclusions may be artifacts of the analytic methodologies employed for data analysis; (3) a well-formulated theory under which path analytic techniques are employed may clarify somewhat the way a variable affects HTL values through its correlational connections with other antecedent variables included in the theoretical model; (4) multicollinearity among independent variables on which HTL is regressed usually presents a problem in unraveling exactly how each variable influences noise-induced hearing loss; and (5) because of the contradictory nature of its direct and indirect effects on HTL, iris color provides little, if any, explanatory assistance for modeling HTL.

Electromyographic feedback treatment for tinnitus aurium.

The relationship between behavioral severity ratings of tinnitus and electromyographic (EMG) activity recorded at the frontalis muscle was investigated in a single adult female. A within-subject, double reversal experimental design was utilized. Although auditory biofeedback procedures were effective in decreasing and increasing EMG activity at frontalis muscle sites, changes in EMG levels were not systematically related to behavioral severity ratings of either tinnitus or annoyance. Psychoacoustic judgements of tinnitus parameters were similarly unrelated to EMG levels. Psychological strategies were developed by the subject that apparently were associated with increases as well as decreases in EMG activity.

Heart rate response audiometry: bases, clinical techniques, and limitations.

Although a great deal of information is available concerning cardiovascular responsitivity to sensory stimuli, little is known regarding the pragmatic application of cardiac response measures to the problems of audiological assessment. Some relationships between arousal systems and cardiovascular function have begun to emerge, and the assessment of communicative behavior using HR response measures has become a more realistic goal, but the clinician who desires to utilize these techniques for audiological evaluation faces serious difficulties until further basic research has been conducted. Eisenberg (9) observed that instrumentation for measuring HR changes to auditory stimuli was research oriented and that measurement of HR data, although holding promise for the future, could not be realistically viewed as a clinical tool for audiological evaluation. Indeed, Eisenberg challenged audiologists to suspend the clinical application of these procedures until sufficient basic research evidence has accumulated to operationally define the problems at hand. Until that challenge is met, cardiotachometry will remain only a potentially rewarding procedure for assessment of the auditory system.

Custom-molded earplug performance: a retrospective study.

The purpose of this study was to determine the effectiveness of custom-molded earplugs in preventing hearing threshold shifts over a long period of time. A stepwise regression analysis was employed to accomodate job related variables including workplace noise level, demographic elements including age, and factors related to hearing including ear history. These variables would be expected to exert considerable influence on hearing threshold shifts. However, workplace noise level absorbed unexpected small amounts of variation in hearing threshold shifts for the textile worker subjects (N = 1517) even when noise level was entered as the only variable on the first step for each analysis. And, baseline hearing values absorbed unexpected large amounts even when entered on the last step. An argument based on these findings is presented suggesting that custom-fitted hearing protection was effective in preventing substantial changes in hearing threshold level during the period of this investigation.

Insert hearing protector effects.

The purposes of this investigation were two-fold: (1) to determine whether differences between measured ear canal diameter and actual earplug size affect sound pressure levels in the ear canal during exposure to high levels of noise; and (2) to determine if individuals would select the insert earplugs that conform to their measured ear canal diameter if the decision were left to them. The results indicate that: (1) very small differences between measured ear canal diameter and actual earplug size affect considerably the sound pressure levels in the ear canal during exposure to high levels of noise; (2) individuals typically select earplugs that are smaller than their measured ear canal dimensions when the decision is left to them; (3) the most skilled technician cannot always determine ear canal sizes due to limitations of available measuring instruments.

The cardiac component of the orienting response: effects of signal intensity, clinical interpretation, and procedural limitations.

The effects of stimulus intensity on the cardiac component of the orienting response were explored in male and female subjects. The acoustic stimuli were 10 recorded repetitions of an identical consonant vowel cluster spoken by an adult male. Heart rate data were obtained for both subject groups at three sensation levels across the baseline heart rate and at 10 stimulus presentation trials. A significant main effect was noted for trials. Significant linear and quadratic trend components were observed, reflecting habituation of the orienting response as a function of trials, and indicating the nonmonotonicity of heart rate change over trials. A lower mean heart rate was observed for Condition Two (20 dB SL) than for either of the other conditions, 10 dB and 30 dB SL respectively. Analysis of group variability and individual subjects' heart rate data suggested limitations in generalizing from group to individual data, as well as a need for further investigation if proper interpretation of single subject heart rate data are to be useful in the clinical situation.

The acoustic reflex and loudness recruitment.

Loudness balance and acoustic reflex tests were conducted on 11 hearing impaired patients. At all frequencies tested, equal loudness judgments made by each patient occurred at acoustic reflex threshold levels in each ear. Test results were classified into three general patterns and a Difference Ratio Quotient (DRQ) expressed the relationship between binaural acoustic reflex and pure tone thresholds. Additional information was derived from the DRQ formula to permit more accurate quantification of recruitment.

Acupuncture and sensorineural hearing loss: a review.

The use of acupuncture for treatment of sensorineural hearing impairment is a controversial subject among physicians and audiologists. Until recently, sufficient experimental data were not available to guide those who manage hearing-impaired children and adults. The purpose of this paper is to review current research evidence regarding the use of acupuncture technics for treating sensorineural hearing loss. In general, experimental evidence regarding such treatment is not encouraging. Patients should be advised of the questionable value of acupuncture for improving sensorineural auditory deficits.

Noise-excluding enclosure for audiometry.

Excessive ambient noise adversely effects the efficiency of hearing conservation programs. Noise-excluding enclosures generally reduce the masking effects of such noise more effectively than standard earphones only. Research has shown, however, that pure-tone thresholds obtained with some enclosures may not be valid. The present study examines one particular type of enclosure, the Audiocup. The results revealed (1) that pure-tone thresholds obtained with Audiocups are almost identical to those measured with standard earphones only and (2) Audiocups more effectively reduce the masking influence of white noise. It is concluded that Audiocups may be used for screening and for threshold audiometry in less than ideal testing environments without fear of invalidating the results.