Effects of discotheque music on audiometric results and central acoustic evoked neuromagnetic responses.

Audiograms and auditory evoked magnetic fields (AEFs) were observed in young male and female adults at different ages before and after being exposed to discotheque music for 4 hours. Sound pressure levels (SPLs) ranged from 95 dB (SPL) up to 130 dB (SPL). After exposure, subjects had temporary threshold shifts up to 20-25 dB, which almost disappeared after 2 hours.

Degeneration of the hearing nerve and its detection by distorted-speech testing.

A detailed description of the physiology of the auditory system (including new essential knowledge) is provided, followed by the description of five morphological levels of acoustic signal analysis, of which four play a significant part in establishing the selection capacity of human hearing. As an essential phenomenon connected with loss of the analyzing capacity of the ear, ascending degeneration of the afferent nerve fibers of the inner hair cells and of the hearing nerve (after destruction of the inner hair cells) develops. A distorted-speech test is submitted that offers a simple and easily performed calculation of a ratio, which value renders a reliable estimation of the pathological analyzing capacity of the ear caused by ascending degeneration.

The effect of impulse noise exposure on distortion product otoacoustic emissions in the awake guinea pig.

Distortion product otoacoustic emissions (DPOAE) are a sensitive detector of outer hair cell (OHC) function and were monitored in awake guinea pigs before and after impulse noise damaging the cochlea (peak intensity 153 dB SPL, rise time < 0.1 ms). Animals had stable DPOAE levels before noise exposure.

[Sensorineural hearing loss in children starting school. Results of a representative hearing screening study].

Audiograms in the 0.5-6 kHz frequency range were taken, using improved audiometric screening methods, in 2032 children, 6-7 years old, who were undergoing their pre-school medical examinations. In 151 children (7.

[Detection of inactivity of the auditory system in the beginning stage with the Freiburg masked speech test].

Late-onset auditory deprivation or "inactivity" phenomenon has been reported in single cases only because it has not been possible to assemble a larger number of calculable cohorts for which all necessary details concerning individual histories are available. Subjects should not be older than 60 years of age and should have had asymmetric hearing for at least about 10 years or should have been wearers of monaurally fitted hearing aids. The development of late-onset auditory deprivation is presented in 6 single cases.

Late-onset auditory inactivity (deprivation) in persons with bilateral essentially symmetric and conductive hearing impairment.

The purpose of this investigation was to examine the effects of prolonged monaural amplification on the suprathreshold speech-recognition scores in the unaided ears of 46 persons with bilateral essentially symmetric and conductive hearing impairment and aided ears of 46 other persons with bilateral essentially symmetric and conductive hearing impairment. All subjects were less than 50 years of age. The suprathreshold speech-recognition loss scores for taped monosyllabic German PB words were analyzed.

[The definition of "selectivity" in reduced speech discrimination as a sequela of peripheral perceptual damage].

The term "selectivity" means the ability to correctly select speech in the presence of other kinds of noise. In the literature the term "selectivity" is used very differently with regard to the different levels of the hearing system. In actual practice a separation of this term is important for possible audiometric topodiagnosis study.

[Experiences with high-frequency hearing tests in the selection of personnel for noise occupations].

A total of 181 persons aged between 16 and 18 were checked fully audiometrically (conventional and high-frequency audiogram). Dates of history about hereditary hearing damage, own ear diseases, noise exposure during frequent visits to discothecs or usage of Walkman etc. were ascertained by questionnaires.

[The accuracy of subjective determination of auditory threshold in the range of 0.5 to 18.0 kHz using different sound transducer systems].

This paper reports on the degree of accuracy of determinations of hearing threshold in the 0.5 to 18 kHz range. As far as possible, these hearing thresholds were compared with those of ISO 389.

[Manifestations of inactivity in unilateral hearing aid management of patients with a high degree of hearing loss].

Concluding from audiometrical practice using hearing aids unilaterally we could find an inactivity of the unused contralateral ear. We have investigated if it is possible to measure this inactivity by common psychoacoustic methods. We tested 92 persons with advanced combined hearing loss.

[Experiences with the distorted Freiburg Speech Test--diagnosis and rehabilitation of hearing disorders].

In accordance with the description of an extended technique of distorted speech at different values - 15 dB, - 10 dB, - 5 dB and 0 dB with the plotted frequency characteristic, we used the procedure with different kinds of sensorineural hearing loss. The method analyse the peripheral hearing system very simply. In cases of acoustic tumours the quotient is very large and it is better to reduce the degree of distortion (-10, -5 and 0 dB).

[High-frequency audiometry for the early diagnosis of occupational acoustic trauma].

We investigated a total of 537 patients (68 men, 469 women) working in the textile industry to ascertain their hearing level in the conventional hearing range as well as in the HF range. The persons tested work at 3 different noise levels (80-84, 85-89 and 90-94 dB [A] Leq). The differences in the hearing thresholds of the three sound level groups mentioned above were checked by means of discrimination analysis.

High-frequency audiometry in the evaluation of critical noise intensity.

We investigated a total of 537 subjects (68 men, 469 women) working in the textile industry to ascertain their hearing level in the conventional hearing range as well as in the high-frequency (HF) range. The persons we tested work at three different noise-levels [80-84, 85-89, 90-94 dB (A), measured as leq). The differences in the hearing thresholds between this three groups mentioned were checked by means of discriminant analysis.

[Assessment of social hearing with a questionnaire in relation to average hearing loss].

In 86 patients with sensorineural hearing loss we checked if the measuring results obtained by conventional audiometric procedures correlate with the subjective impression of hard hearing ascertained via a special questionnaire. For this purpose we compared the average hearing loss (500, 1000, 2000 Hz) of the puretone audiogram with the results obtained via the questionnaire developed by v. Wedel and Tegtmeier for assessing the social hearing handicap (SHH).

[The problem of critical intensity].

We investigated a total of 537 patients (68 men, 469 women) working in the textile industry to ascertain their hearing level in the conventional hearing range as well as in the HF range. The persons tested work at 3 different noise levels (80-84, 85-89 and 90-94 dB (A) Leq. The differences in the hearing thresholds of the three sound level groups mentioned above were checked by means of discrimination analysis.

Influence of different kinds of noise on the ear and some physiological and psychological parameters.

The reactions of the human organism to noise are complicated and difficult to separate from other stressors, with the exception of hearing damage. After thorough experimental planning and a rigorous selection of sample persons, the reaction to noise of varying structures was studied by reactions of heart rate, blood pressure, reaction time, the temporary threshold shift (TTS) of hearing and the psychological parameters "Mood" (in German "Befinden"). We found a special kind of TTS dependent on the structure o noise and no effect of physiological parameters.

High frequency hearing following otitis media with effusion in childhood.

78 children had been treated for secretory otitis media at the age of 4.4, on the average. At the age of 18.

[Distorted Freiburg Speech Test].

In 107 patients with different types of hearing loss (air conduction, sensorineural and combined) we ascertained the monaural discrimination loss of monosyllables with the help of the normal and distorted Freiburg speech test. It was evident that the quotient obtained from the measured discrimination is a very good and useful measure to characterise the ability to analyse the peripheral hearing system. Compared with normal hearing individuals and patients with air conduction hearing loss or combined loss of hearing, persons with perception hearing loss show a much greater and more divergent quotient.

[Ultrasound perception in deaf patients (author's transl)].

The acoustic evoked potentials (AEP) of 100-300 ms latency, evoked by ultrasound irritation (20-80 kHz) in normal hearing subjects cannot be derived from deaf persons. There was no reaction of 10 patients with congenital or acquired deafness during ultrasound - ERA - examination according to the absent subjective hearing perception.

Efficiency of subjective audiometry in children up to the third year of age.

After a discussion of possible methods for measuring the hearing of infants, we present a more appropriate method which we have developed and used over a number of years. The method applied is called "sound orientation audiometry" and is based on the readiness of infants to seek out the sources of sounds. As the infants are observed by means of a one-way mirror, no distraction is possible.