High-tone Loss Research Articles

Abrupt High Tone Loss in Perceptive Hearing Impairement

Abrupt High Tone Loss in Perceptive Hearing Impairement

Hearing Loss and Drilling Noise

The possible cochlear lesion caused by drilling noise was studied after simple or modified radical mastoidectomy by following the hearing of both the operated and the contralateral ear. In 29/70 cases a temporary sensorineural high tone loss of at least 10 dB in one of the frequencies 4–8 kHz was found in the operated ear; of these, 14 also showed such a loss in the contralateral ear. In addition, 2 cases showed hearing deterioration in the contralateral ear but not in the operated one, and in another case the operated ear was deaf before surgery. If bilateral, the hearing loss was generally more severe in the operated ear. Thus, there may be at least two mechanisms of inner ear lesion during chronic ear surgery: direct surgical trauma and drilling noise during the operation.

Clinical Observation of Benign Paroxysmal Positional Vertigo

Forty-fire patients with benign paroxysmal positional vertigo were clinically investigated. The results were as follows:1. Thirty-two of the 45 (71%) were in their forties through to sixties, in other words, in middle-and old age.2. On audiograms, 21 of the patients (41%) showed the high tone loss and C5 dip type. However, 22 of the patients (48%) were of normal hearing.3. About the past history such as head trauma, otitis media, etc., no remarkable findings were observed.Five cases of paroxysmal positional vertigo were then presented, and the location of lesion was discussed. The lesion responsible for paroxysmal positional vertigo seemed to be located in the otolith organs. But, in several cases, no define origin of this disease was definable. Much more experience and investigation seemed to be needed.

A lower audiometric limit for auditory brainstem response (ABR).

A lower audiometric frequency limit for reproducible ABR in response to 75 dB and 85 dB nHL 2.0 kHz haversine wave stimuli was defined by testing subjects with steep high-tone loss of varying cut-off frequencies. The limit between audiograms with and without reproducible ABR passed roughly through 40-50 dB HL at 500 Hz and 80-90 dB HL at 1000 Hz. Lack of ABR was not equivalent to lack of potentially useful hearing.

Änderung des Spitzendrucks und der Frequenz des Impulsschalls vom Freifeld zum Ohr in seiner Bedeutung für das akustische Trauma des Ohres

Bei Impulslärm ist im Gehörgang vor dem Trommelfell ein etwa 5-10 dB höherer Spitzendruck und eine Frequenzverschiebung des Knallspektrums in Richtung höherer Frequenzen gegenüber der Freifeldmessung vor dem Ohr nachweisbar. Für die Bewertung der akustischen Belastungsgrenzen und der Dämmwerte der Hörschützer ist dies von Bedeutung. Die Verschiebung in Richtung höherer Frequenzen durch die Resonanzwirkung des Gehörgangs sollte zur Erklärung der knallbedingten Hochtonsenke herangezogen werden.

�nderung des Spitzendrucks und der Frequenz des Impulsschalls vom Freifeld zum Ohr in seiner Bedeutung f�r das akustische Trauma des Ohres

In case of impulse noise peak level is enlarged about 5–10 dB in the auditory meatus. The spectrum of the noise is changed in direction of higher frequencies. This is essential for damage risk criteria of impulse noise and judgement of protectors. The resonance of the meatal cavity should be considered for explanation of high tone loss through impulse noise of high energy.

Clinical Application of Non-Invasive Electrocochleography

Non-invasive extratympanic electrocochleography (ECochG) was performed in normal-hearing subjects and patients with sensorineural deafness. Action potential (AP) threshold, N1 input-output function, waveform, summating potential (SP) are presented. AP thresholds were within 15 dB in normal-hearing ears and within 30 dB in hearing-impaired ears above subjective thresholds for the click. Correlational analysis showed that click-evoked AP thresholds are best correlated to pure tone thresholds at 2 to 4 kHz. Four types of N1 input-output functions were classified. Normal functions appeared in moderate high tone loss only at 8 kHz and low tone loss with almost normal threshold above at 4 kHz. Many ears with a flat loss had recruiting responses, while many ears with a high tone loss had either dissociated responses or responses with prolonged latency. Several types of waveforms were distinguished. Enhanced--SP was observed in Meniére's disease and late congenital syphilis to which endolymphatic hydrops is common. The clinical value of the non-invasive ECochG is discussed.

Electrocochleographic Study of Meniere's Disease

Electrocochleography (ECOG) reflects the functional state of the cochlea, and can be used as a tool of clinical otology. It is thus valuable when making a diagnosis of the different pathological conditions which affect the cochlea.In the present series, 16 ears in patients with Meniere's disease were examined by ECOG. As a control, 6 normal hearing ears and 10 high tone loss ears also served as subjects. Short tone bursts were used as stimuli, and the trans-tympanic recording method was used.Main findings in the case of Meniere's disease are summarized as follows.(1) The N1 thresholds were similar to the subjective ones.(2) The waveforms of the AP-SP potentials recorded in Meniere's cases were broad.(3) Both in Meniere's ears and high tone loss ears, a positive summating potential (SP+) was recorded when using high frequency tone bursts.(4) In the ears of those with Meniere's disease, the large negative summating potential (SP-) was obvious for low frequency tone bursts.(5) In the fluctuant stage of hearing loss, the negative summating potential (SP-) amplitude related to the attack of Meniere's disease, but not to the degree of hearing loss.(6) In those with Meniere's disease, the input-output curves of N1 amplitude were rather steep compared to normal ears, and a steep slope thus was indicative of a positive recruitment.(7) In the late stage of Meniere's disease, the difference between those with the disease and those with a high tone loss was not evident using ECOG.

Diving injuries to the inner ear.

Two skin divers and 7 SCUBA divers, all men, aged 21–33 years, are presented. The injury occurred at shallow depths and difficulties with pressure equilibration to the ears were a common complaint. Vertigo and hearing losses. When a perilymph fistula is suspected and decompression sickness can be in the round, the other in the oval window. The latter patient also had a perforated ear drum on the same side, but his hearing normalized after surgical repair of the fistula and perforation. The others suffered lasting sensorineural high tone losses. When a perilymph fistula is suspected and decompression sickness can be ruled out, surgery within two days is recommended if bed rest does not prove effective.

Ear Damage Due to Diving

Diving injury may affect all parts of the ear during all types of diving. Divers are regularly exposed to noise and 120 dB(A) is measured during ventilation of a hyperbaric chamber. Ear canal squeeze, possibly with drum perforation, may give a transient conductive hearing loss. Middle ear squeeze, possibly with drum perforation, also gives a transient conductive loss. Inner ear barotrauma, possibly with perilymph fistula, most often results in transient vertigo and lasting sensorineural high tone loss, often resembling a noise-induced loss. Decompression sickness and gas embolism can also damage the inner ear. A change of breathing gas during deep diving has damaged the labyrinth, most likely due to counter diffusion. The authors have seen two cases of over window perilymph fistula resulting from diving. One of them also suffered a burst ear drum on the same side. His hearing returned to normal after surgical repair.

Results of hearing testing at 7-year follow-up of kanamycin-treated newborn infants.

A follow-up study 7--8 years after kanamycin treatment of 83 newborn infants in the Tampere University Central Hospital is described. The Apgar scores ranged from 1 to 10, about half of the patients being premature. Only in 1 case (1.2%) a slight bilateral high-tone loss was found. This patient's birth had been complicated by ablation of the placenta with subsequent cesarean section and he had neonatal sepsis as well. The cause of this hearing defect is thus not necessarily the use of kanamycin. Because of the extended use of reserve antibiotics, microorganisms resistant to modern antibiotics may necessitate in some vital cases the use of kanamycin. Our results indicate that, if serum concentrations are monitored adequately, the use of kanamycin does not necessarily result in a hearing defect.

Development of the California Consonant Test

A 100-item, multiple-choice test for consonant identification labeled the California Consonant Test (CCT) has been developed expressly for use with hearing-impaired patients. A computer-assisted analysis was obtained for the test responses of 550 patients with sensorineural hearing loss. The test seems highly sensitive to configurations of high-tone loss, but the correlation with degree of loss, especially in the instance of flat configurations, is somewhat low (-0.40). Test-retest correlation is 0.96. A correlation of 0.35 with a W-22 list indicates that the two tests are measuring different aspects of speech reception. In addition to its usefulness in identifying consonant confusions for rehabilitation purposes, the CCT may prove helpful in ranking hearing aids. For the latter purpose, two 50-item subforms, designed for equivalence, have been under observation for possible use when time is a critical factor. Repetitions of the 100-item list offer greater stability, however.

Auditory Findings in 33 Cases of Acoustic Neuromas

The audiological findings of 35 ears in 33 cases with surgically confirmed acoustic neuromas were presented. One of 35 affected ears had normal hearing, 17 hearing loss of varying degree, 17 total deafness. Hearing patterns of 18 ears with preserved hearing were divided into 3 types: (1) high tone loss, (2) moderate flat loss, (3) severe flat loss. A clear connection between the degree of hearing loss and tumor size was noted. The larger the size of tumor, the greater the degree of hearing loss. Cochlear type of abnormality was found for the small- or medium-sized tumors, retrocochlear type for medium- or large-sized tumors. The mechanism of hearing loss in acoustic tumors was discussed. In cochlear type of hearing loss, the diagnosis of acoustic tumor should not be excluded.

A clinical study of abrupt high tone loss

A clinical study of abrupt high tone loss

Clinical Evaluation of the Auditory-Evoked Brain Stem Response (BSR) in the Prediction of Pure Tone Thresholds

BSR audiometry was administered to 20 normal and 44 hearing impaired subjects. The hearing impaired group consisted of 15 subjects with flat loss, 17 high tone loss and 12 low tone loss. One-and-a-half cycles of a 500Hz sinusoidal wave (500Hz click) and one cycle of a 3kHz sinusoidal wave (3kHz click) were used as stimuli. Intensities of these stimuli were calibrated by the averaged subjective threshold from 20 normal hearing ears. (dBHL)In normal subjects, the averaged threshold of the BSR evoked by a 500Hz click was 13.1dBHL and by a 3kHz click, 4.2dBHL.BSR frequency specificity was determined by measuring the BSR (to 500Hz and 3kHz clicks) in hearing impaired subjects. The 500Hz click evoked a BSR in subjects whose pure tone audiograms were impaired above 500Hz. Also, in cases of low tone hearing loss, the BSR was evoked at the best-hearing frequency above 500Hz. The 3kHz click evoked a BSR in subjects with hearing impairment above 1kHz.These results indicate that the BSR provide information regarding hearing ability as low frequency as 500Hz.

Sensori-Neural Deafness in Two Cases of Progressive Muscular Atrophic Diseases

Two cases of hearing disorders with progressive muscular atrophic diseases were reported. The case 1 is an 11-year-old boy with facio-scapulohumeral type of muscular dystrophy, whose audiogram showed the sensorineural type of bilateral deafness with gradual form of high tone loss. The case 2 is a 29-year-old female with congenital multiple arthrogryposis complaining of progressive hearing impairment of both ears. The audiogram showed sensori-neural deafness. Her hearing acuity became worse as the muscular atrophy proceeded. The hearing impairment of both cases might be due to the pathological change in the inner ear because they had recruitment phenomena and bone conduction disorders.

Consonant confusions associated with hearing loss above 2000 Hz.

A 100-item test for the identification of phonemes was presented to two groups of listeners. One group consisted of 35 patients with normal hearing up to 2000 Hz accompanied by a high-tone loss. The other group consisted of persons with normal hearing who heard the speech stimuli presented through a low-pass filter with a cutoff at 2040 Hz. There were no significant differences between the two groups in overall scores, in probabilities of error for individual phonemes, or in the kinds of error substitutions made. Findings were as follows: (1) the overall scores indicated difficulty in phonemic identification; (2) the phonemes contributing to this difficulty were primarily /b, p, t, k, s, θ/ in both the initial and final positions, /t∫, ∫, f, dƷ, z, v/ in the final position only, and /d/ in the initial position only; and (3) the phonemes substituted for the stimulus phonemes in the initial position were the same in manner of articulation as the stimulus phoneme, and typically only one confusion occurred per stimulus phoneme. The phonemes substituted for the stimulus phonemes in the final position were not necessarily the same in manner of articulation as the stimulus phoneme, and more than one confusion generally occurred for each stimulus phoneme.

Detailed Audiometry

Very slow frequency sweep (5 minutes and 40 seconds per 1 octave) was adopted in ordinary Békésy audiometry as a new method for detailed measurement of hearing threshold along the frequency scale. The purpcse of this paper is to ascertain the limitation of this method in the viewpoint of exact recording of the threshold curve. One hundred and three ears with high tone loss of abrupt or dip type were tested. As the result, it was observed that the correct threshold was obtained in 101 ears, and only two ears showed so sharp slope of the threshold curve that the trace coincided the maximum limit of this recording. Accodingly, it was concluded that the usefullness of this method was recognized.

Some Examinations to Determine the Best Frequency Characteristic of Hearing Aids for Patients with Hearing Loss in the High-Tone Range

The purpose of the present investigation was to study the possibility of improving the hearing aid treatment of patients suffering from high tone loss with recruitment. Unlike previous projects of similar character where the aim was to obtain maximum speech intelligibility, our aim was to determine the frequency response curve giving the most comfortable sound impression for the patient. With this in mind our hypothesis is that the optimal frequency response will depend upon the input sound pressure. It is postulated that the frequency response should be flat up to a given frequency, the audiogram's cut off frequency, and thereafter should rise with a variable slope to a certain level (treble amplification), slope and treble amplification being functions of input sound pressure level. Ten patients were examined with response curves synthesized on laboratory equipment using earphone presentation. Current speech was used as test signal. In the first part of the examination the test promotor chose at random ...

Comparison between Intelligibility of A) Low Pass Filtered Speech by Normals and by Persons with a Corresponding High Tone Loss and B) of Low pass Filtered Speech and High Pass Filtered Speech

Comparison between Intelligibility of A) Low Pass Filtered Speech by Normals and by Persons with a Corresponding High Tone Loss and B) of Low pass Filtered Speech and High Pass Filtered Speech