摘要:

ABSTRACTTwo acoustic immittance screening procedures were evaluated in conjunction with pneumatic otoscopy, performed by a pediatric otolaryngologist. The subjects were 204 3-and 4-yr-old children from a rural area in eastern North Carolina. Pass-fail criteria were examined using two middle ear screening procedures: (1) a “traditional” procedure based on measures of tympanometric peak pressure and acoustic reflexes, and (2) the tympanometric measures contained within the American Speech-Language-Hearing Association's (ASHA) revised Guidelines for Screening for Hearing Impairment and Middle Ear Disorders. The traditional procedure resulted in low specificity but high sensitivity, whereas ASHA's immittance procedure resulted in high specificity but only moderate sensitivity. The negative predictive value was very high for both procedures; however, positive predictive value was low, especially for the traditional procedure. Advantages and disadvantages of the two procedures and future research needs are discussed.

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTSpeech intelligibility scores from 16 subjects with senso-rineural hearing loss were evaluated using a digitized version of the California Consonant Test that was presented via headphones through a 300 to 3000 Hz bandpass filter to simulate the telephone band. Each subject was tested with an unprocessed signal that was frequency-equalized to compensate for the individual's hearing loss, and a signal that was equalized and compressed by the use of a compressor compression technique. Subjects were tested at three sound pressure levels above a pure-tone average threshold for frequencies 1 and 2 kHz. Two digital signal processing techniques designed to compensate for high-frequency hearing loss were examined: frequency domain processing and time domain processing. Frequency domain involved modification of the short-term spectrum obtained through a fast Fourier transform, whereas time domain processing involved passing the signal through a bank of finite impulse response filters. Both techniques showed significant intelligibility improvements (15-3070). In a second experiment, 16 additional subjects with high-frequency hearing loss compared an amplified telephone signal to three processed signals: (1) 6 dB per octave emphasis; (2) a signal frequency equalized for their hearing loss; and (3) a signal that was equalized for their hearing loss and was compressed according to their uncomfortable loudness levels. Most subjects preferred the signal with the 6 dB per octave emphasis.

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTForty-eight normal-hearing subjects performed ease of listening, word recognition, and attentional effort tasks for speech in noise under binaural and two simulated unilateral conductive hearing loss (monaural) conditions. The two monaural conditions differed as a function of unoc-cluded ear orientation to the primary signal (monaural-near and monaural-far). Ease of listening ratings and word recognition scores were significantly poorer during monaural listening and significantly affected by ear orientation to the speech signal. Attentional effort was not significantly affected by changing from binaural to monaural-near listening, but was significantly poorer in the monaural-far condition than in either of the other listening conditions. There was a significant correlation between ease of listening ratings and word recognition, but no correlation between attentional effort and either ease of listening or word recognition. (Ear Hear 13 2:80-86)

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTAuditory brain stem responses were obtained from normal-hearing infants and adults in response to bone-conducted 500 and 2000 Hz tones presented in quiet and high-pass noise masking. The tones were presented at 70 (500 and 2000 Hz) and 46 (2000 Hz) dB peak to peak equivalent (re: 1 dyne RMS). The high-pass noise-masked waveforms were subtracted in succession to obtain derived responses, providing estimates of the cochlear regions contributing to the nonmasked responses. Findings indicate that the auditory brain stem response to bone-conducted 500 Hz tones is frequency specific for both infants and adults. For 2000 Hz tones, the results show maximum amplitudes for cochlear regions representing the nominal frequency of the tone for adults. For infants, maximum response amplitudes for the derived responses to 2000 Hz, 70 dB tones were obtained within 1/2 octave of the nominal frequency (1410-2000 Hz). Wave V latencies of the derived responses are similar for both groups for 2000 Hz tones, but shorter for infants to 500 Hz tones, supporting the hypothesis that low-frequency bone-conducted stimuli are effectively more intense in infants than adults.

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTAn estimate of the traveling wave velocity (TWV) was evaluated in 18 young adults to determine the technique's applicability as a possible tool in evaluating Meniere's disease. This TWV estimation uses a derived auditory brain stem response procedure requiring high-intensity masking. The results indicate that on average, TWVs were similar to those obtained via psychophysical measures or electrocochleography. However, instances of undermasking, due to subjects' intolerance, resulted in a number of subjects exhibiting faster than expected TWVs.

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTThe use of FM systems as primary amplification for children with severe and profound hearing loss is discussed. The FM advantage for improving speech perception and for reducing the detrimental effects of distance, noise, and reverberation is described. Both hypothetical and actual cases are used to demonstrate the FM advantage. An evaluation method for selecting an appropriate FM system is described.

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo evaluate whether age, education, functional handicap, degree of hearing loss, amount of hearing and speech recognition gain achieved with hearing aid, locus of control, visual acuity, manual dexterity, number of co-morbid diseases, and number of medications predict which elderly individuals with hearing loss are likely to benefit from hearing aids.DesignA logistic regression prediction model for hearing aid benefit was developed on a training set of 89 individuals and verified in a test set of 87 individuals. Hearing aid success was assessed 4 mo after hearing aid administration. It was defined by assessing hearing aid satisfaction, functional handicap change post-hearing aid, and number of hours of weekly hearing aid use.SettingAll patients were elderly male veterans from the Audie L. Murphy Memorial Veterans Hospital. There were no differences in demographic or clinical characteristics in training versus test set individuals.ResultsSeveral variables, including baseline perceived functional handicap, education, number of medications, and age correlated with individual success measures. However, no variables consistently correlated with all success measures. The accuracy of prediction rules for success utilizing the variables ranged from 75 to 88% in the training set, and 54 to 84% in the test set.ConclusionAlthough certain baseline factors were statistically significantly related to individual measures of successful hearing aid use, no factors were good enough to consistently differentiate successful from unsuccessful hearing aid candidates. (Ear Hear 13 2:108-113)

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTAutomatic frequency response (AFR) hearing aids usually reduce their low-frequency gain in the presence of noise; several investigators have reported improved recognition of high-frequency speech information in low-frequency band-limited noise with AFR versus non-AFR hearing aids. In this work, masking patterns (masked threshold for frequency-modulated probe tones as a function of probe frequency) were obtained for a narrowband low-frequency noise. Speech recognition threshold for a set of high-frequency loaded monosyllables also was obtained in the presence of the same noise. Aided speech and masking pattern data for one normal and two hearing-impaired subjects wearing a master hearing aid incorporating a commercially available AFR circuit showed modest AFR effects. Moreover, masking noise spectra measured in ear canals of subjects wearing the master hearing aid showed evidence of substantial hearing aid-generated distortion products in the AFR-off condition. Results obtained from the normal subject listening with a low-distortion laboratory simulation of an AFR hearing aid showed greater release from masking for the same low-frequency attenuation as provided by the hearing aid. Improvements of speech recognition in noise observed with AFR hearing aids may result from some combination of release from upward spread of masking and reduction of distortion products generated by the hearing aid in the non-AFR setting. (Ear Hear 13 2:114-121)

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ABSTRACTHearing aid users with longstanding and severe dermatitis in the ear canal were examined by a dermatologist and patch tested. In 6 of 22 (27%) patients, contact allergy to the earmold material was found. Four of the six had a positive test reaction to methyl methacrylate and two also to triethyleneglycol dimethacrylate and urethane di-methacrylate. Positive patch test reactions to substances used for topical treatment were found as well. Routines including liberal patch testing for this group of patients are suggested.

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID

ISSN:0196-0202    

出版商:OVID    

年代:1992

数据来源: OVID