Journal of the American Auditory Society最新文献

Thirty normal hearing subjects were utilized in an investigation designed to determine the extent to which guessing on the part of the listener may influence the speech reception threshold. Results suggest that the magnitude of the speech reception threshold may be significantly altered as a result of the degree of guessing which occurs during the administration of the test. Clinical implications of this finding are discussed.

A summary of the results shows that with 5 of the 9 subjects the high-frequency consonant scores indicated the same aid for the patient that the NU-6 scores indicated. In 2 cases the NU-6 indicated amplification was appropriate whereas the high-frequency consonant scores indicated amplification was not appropriate. Obviously, the high-frequency consonant scores should be considered supplemental to the NU-6 scores and not as a replacement for the NU-6. The combination of the NU-6 and the high-frequency consonant results for Subject 1 may indicate that the patient should have received further counseling and should have been taught how to communicate more effectively without an aid. The high-frequency consonant scores obtained by 2 of the subjects indicated different aids than the ones indicated by the NU-6 test and the patient preference. Perhaps the reason the patient chose an aid other than the one that would most benefit him was that he was most comfortable with the aid that allowed him to hear in the manner to which he was accustomed, even if he did not do as well with it. If a person had become accustomed to not hearing the high-frequency sounds, an aid that suddenly allowed him to hear those sounds might disturb him. The addition of high-frequency amplification might have made speech sound foreign to him. It would have been much easier for him to choose the aid that he was most comfortable with.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic reflex thresholds were measured for eighteen young adults (9 men and 9 women) at four different blood alcohol levels: 0.00%, ascending 0.10%, 0.15% (peak level), and descending 0.10%. Reflex-eliciting stimuli consisted of three narrow-band noises (300 to 600, 600 to 1200, and 1200 to 2400 Hz) and three broad band noises (white noise, recorded rock music, and recorded factory noise). Prealcohol reflex thresholds were found to be significantly more sensitive than all postalcohol reflex thresholds for all stimuli, and broad-band stimuli demonstrated greater threshold shifts than did narrow-band stimuli. Significant sex differences were not observed for any blood alcohol level. Between subject variability was high, with 10 subjects showing little or no reflex threshold change and the other 8 subjects showing dramatic threshold changes.

Consonant perception was investigated for 120 normal-hearing adults who listened to 16 consonants in a phrase context and made similarity judgements of 256 diadic stimulus pairs on a 9-point equal-appearing interval scale. Stimuli were presented at subjects' most comfortable listening levels in 3 low-pass filtered and one nonfiltered conditions. Subjects' ratings were converted to 16 X 16 full symmetric similarity matrices and submitted to INDSCAL analyses. Results revealed perceptual features common to all groups, as well as group-specific features (i.e., sibilancy, stop/continuancy, and place for nonfiltered; plosive and place for 4000-Hz low-pass; stop/continuancy and place for 2000-Hz low-pass; and voicing and stop/continuancy for 500-Hz low-pass). These results were similar to those found earlier for hearing-impaired subjects having sensorineural losses compatible with these frequency cut-offs.

When a low-intensity stimulus A is alternated in time with a high-intensity stimulus B of relatively short duration, stimulus A is heard as continuous. This "continuity" effect is shown to occur even when the B stimulus is a series of sharp pulses at one rate and the A stimulus is a series of pulses at another rate which must produce a very different neural temporal pattern. Simple substitution models of the continuity effect are thus shown to be inadequate. A model is presented to make various types of continuity effects more understandable.

The sound fields in which hearing aid evaluations are performed with tests of speech discrimination are far from standardized. This investigation was concerned with the nature of the sound field in terms of separation of speech and noise sources as related to the optimal setting of a master hearing aid as indicated by listener performance scores on tests of speech discrimination in noise. Two sound fields were used in this investigation, one with speech and noise from the same source and another with speech and noise sources separated by 90 degrees and 45 degrees off the axis of the midsagittal plane of the listener. The repeatability of the optimal setting of the master hearing aid from one configuration to the other and the resolution available in each sound field, were of prime interest. The data indicated that the sound field configuration has no bearing on the optimal setting of the master hearing aid. The data did indicate that maximum resolution was available in the case of speech and noise from the same source.

Conductance and susceptance measurements at probe frequencies of 220 and 660 Hz from eleven children's ears at intervals of 1 min, 10 min, 1 day, and 1 week (7 to 10 days) were obtained utilizing the Grason-Stadler Otoadmittance Meter model 1720. All test-retest correlation coefficients were found to be statistically significant (p less than 0.05); therefore, reliability of tympanometric measures using this instrument with children seems to be adequate for clinical use.

Two groups of subjects, 50 noise-exposed and 50 non-noise-exposed, both with unilateral conductive hearing loss, were studied in terms of the amount of conductive hearing loss and difference in the bone conduction thresholds at 4 kHz between the two ears. The results support the hypothesis that middle ear disorders provide the ear some protection from noise-induced hearing loss.

The purpose of this investigation was to determine whether masking level differences (MLD's) could differentiate between normal children and children with suspected auditory processing problems. MLD's for speech and 500-Hz tones were measured for an experimental group consisting of 24 normal-hearing children suspected of having auditory perceptual dysfunction. Fourteen children with normal auditory processing abilities and 11 normal-hearing adults comprised the control groups. Results indicated that (1) there was no difference between MLD's for "normal" children and normal adults; (2) there was no difference between speech MLD's for the two groups of children; however, (3) tonal MLD's for the children with suspected auditory perceptual problems were significantly lower than those for the normal groups. Using a cut-off tonal MLD of 7 dB, 79% of the experimental group were positively identified whereas only 12% of the normals were identified. The tonal MLD can be a strong addition to a central test battery, especially because it can be used with nonverbal children who cannot complete many tests because of limited linguistic skills.