Audiology : official organ of the International Society of Audiology最新文献

In this study, the parameters of notches in the Audioscan have been compared with the distortion product otoacoustic emission (DPOAE) findings in 100 subjects with normal hearing, including 55 normal controls and 45 patients with King Kopetzky syndrome. Of those, 35 subjects had Audioscan notches (11 controls and 24 patients), 96 per cent (53 out of 55 notches) of which were associated with notches in DPOAEs. Analyses showed that the notch centre frequencies obtained in the Audioscan test correlated significantly with those of the notches found on the distortion product audiogram (DP-gram). In addition, the width of notches of the two procedures was also significantly correlated. It is likely, therefore, that such notches on Audioscan and DPOAE testing reflect localized areas of impaired cochlear function.

Evaluation of cochlear hearing loss by means of transiently evoked otoacoustic emissions is already established in clinical practice. However, accurate prediction of pure-tone thresholds is still questioned and is still regarded as troublesome. Both click- and tone-burst-evoked otoacoustic emissions at several intensity levels were measured and analysed in 157 ears from normally hearing and 432 ears from patients with different degrees of pure sensory hearing loss using the ILO88/92 equipment. Results of otoacoustic emissions (OAE), elicited by clicks and tone-bursts at centre frequencies from 1 to 5 kHz, were analysed using two different statistical methods. Both multivariate discriminant analysis and forward multiple regression analysis were used to determine which OAE variables were most discriminating and best at predicting hearing thresholds. We found that a limited set of variables obtained from both tone-burst and click measurements can accurately predict and categorize hearing loss levels up to a limit of 60 dB HL. We found correct classification scores of pure-tone thresholds between 500 and 4000 Hz up to 100 per cent when using combined click and tone-burst otoacoustic measurements. Prediction of pure-tone thresholds was correct with a maximum estimation error of 10 dB for audiometric octave frequencies between 500 and 4000 Hz. Measurements of multiple tone-bursts OAEs have a significant clinical advantage over the use of clicks alone for clinical applications, and a good classification and prediction of pure-tone thresholds with otoacoustic emissions is possible.

The purpose of this study was to assess the accuracy, in older adults, of questions assessing hearing loss. Study participants (n=3,556), aged 48-92 years, were examined in a population-based study of age-related hearing loss in Beaver Dam, Wisconsin. Self-report data from the ten-question Hearing Handicap Inventory for the Elderly-screening Version (HHIE-S), and four additional questions were compared with hearing loss as measured by pure-tone air conduction audiometry. The single question, 'Do you feel you have a hearing loss?' was the most sensitive question (sensitivity=71 per cent); its overall and gender-specific prevalence estimates were within 3.2 per cent of prevalence measures derived audiometrically, although age-group specific estimates were not as accurate. Using an HHIE-S total score >8 resulted in low sensitivity (34 per cent) and inaccurate prevalence estimates. These results indicate that, for some applications, one simple question may be sufficient for prevalence surveys of hearing loss among older adults.

In pre-term infants, spontaneous otoacoustic emission (SOAE) frequencies show an upward shift with time. The present study aimed to monitor the SOAE amplitude variation during this frequency shift. A long-term observation of 87 SOAE frequencies from 18 pre-term infants yielded a positive frequency shift of 0.72 per cent per week, which was not accompanied by a simultaneous amplitude shift, as the mean variations in SOAE amplitude were practically zero. Furthermore, there was no relationship between the short-term SOAE amplitude variation and the infant's post-conceptional age. Only the absolute amount of SOAE amplitude variation seemed to grow with time. Comparison with induced variations in SOAE frequency argues against a middle ear influence on the SOAE frequency shift. In our view, the absence of any amplitude shift during the upward SOAE frequency shift further suggests cochlear development during the last period of gestation.

Vocalizations often have periodic variations of their acoustic waveform envelope. Two simultaneously presented frequencies have an envelope fluctuation with a frequency equal to their difference tone (DT = F2-F1). Sinusoidal amplitude modulation (SAM) of a carrier frequency also produces an envelope fluctuation. Electrical ensemble responses to DT and SAM stimuli were recorded from the gerbil's round window. The predominant frequency of the response to the DT stimuli is F2-F1; to the SAM stimuli, it is the modulation frequency. Both responses are spectrally, temporally, and dynamically non-linear. Forward masking of a low-frequency DT response produced a tuning curve (TC) with a tip at the high-stimulus frequency. Forward masker TCs of a low-frequency SAM ensemble response had tips at the high frequency of the carrier. Tip thresholds and sharpness of tuning of DT and SAM TCs are quite similar, with cochlear neurons having high characteristic frequencies providing sharply tuned information about low frequency acoustic envelope periodicities.

Menière's disease and fluctuating hearing loss are related to labyrinthine fluid pressure variations. The development of a new indirect method of analysis of the tympanic membrane displacement during the stapedial reflex, using the Marchbanks Measurements System (MMS 10), allows us to study inner ear fluid pressure during these pathological conditions. In this study, measurements with this method were made in four groups of patients: a control group with normal hearing (n=7), stable sensorineural hearing loss (n=9), fluctuating hearing loss (n=8), and Menière's disease (n=25). Results show, first, a good relationship between the recording of negative curves, suggesting a high pressure, and the acute episodes of fluctuating hearing loss; and, secondly, in the case of Menière's disease two types of situation: positive and negative curves suggesting normal and high pressures, respectively.

This study investigates the extent to which individuals see themselves as being handicapped by a hearing disability. Self-reports were obtained with the Amsterdam Inventory for Auditory Disability and Handicap which distinguishes five basic disabilities: intelligibility in noise, intelligibility in quiet, localization of sounds, distinction of sounds and detection of sounds. Responses of 239 hearing-impaired people with varying types of hearing loss have been examined. The occurrence of the five disabilities in the population as well as the self-reported limiting and annoying effect per disability has been examined. This study shows that the handicapping effects of the disabilities do not have equal weights. Handicap resulting from the inability to understand speech in noise is most strongly felt. This paper argues that the type of disability jointly determines the severity of a person's handicap.

Since adequate and reliable earphones are now available and standards have been established, clinical audiometry can be performed at extended high frequencies (EHFs). In the present study, 47 preschool children (aged 4-7 years) were examined with EHFs (8-16 kHz) using the new Sennheiser HDA 200 earphone. The hearing thresholds correspond to those of other studies; the median thresholds and range increase with increasing frequency. The medians and quartiles were: 10 kHz: 25 (5-35) dB(SPL), 11.2 kHz: 35 (20-40) dB(SPL), 14 kHz 40 (30-50) dB(SPL) and 16 kHz: 50 (40-60) dB(SPL). The hearing thresholds could be more reliably determined in the older children (> 5 years) and were 5 dB better than in the younger ones (< 5 years). Thresholds in the 10-12.5 kHz range correspond to those of adults but are more sensitive by 5-12 dB in the 14-16 kHz range.

Hearing in elderly people was investigated in an epidemiological longitudinal study (H70) encompassing a cohort representative of an urban Swedish population born in 1901-02. The participants in the study were followed audiometrically over a 20-year period from 70 to 90 years of age. This study focused on hearing and its decline during the later time span in which the participants were tested at the age of 85, 88 and 90 years. The results revealed that hearing loss in advanced age progressed only slightly in both men and women. The annual hearing threshold decline was about twice as large in the eighth decade of life as compared with the ninth. Hearing function was similar in the respondents tested at the out-patient clinic and in those tested at home. There were no consistent indications that survivors to a great age showed better hearing at entry to the study at 70 years of age. Some gender differences were found and are discussed.

Thirty patients with Menière's disorder, 11 patients with cochlear hearing loss of other aetiologies and 10 normally-hearing subjects, were investigated using transtympanic electrocochleography (TT ECochG). Alternating polarity clicks, condensation and rarefaction clicks and long tone-bursts of 1 kHz were used for stimulation. The latencies of the AP responses to click stimulation were evaluated. It was found that the latency differences between the condensation and rarefaction click-evoked responses were significantly larger in patients with Menière's disorder as compared to normal subjects and to patients with other cochlear hearing losses. It was found that the sensitivity of TT ECochG, obtained by using measurements of SP-AP ratios and the SP amplitude at 1 kHz burst stimulation, increased from 83 per cent to 87 per cent by addition of the con-rar shift measurement. The specificity of TT ECochG obtained by this combination of variables was 100 per cent in our material. The results of the study indicate that the latency shift found in responses evoked by clicks of opposite polarities in TT ECochG, can be a useful parameter in the detection of suspected endolymphatic hydrops.