摘要:

The amplitude of theN1responses (guinea pig) to successive members of a train of brief tone pulses falls progressively over the first few members. The effect lessens as the interpulse interval is increased (10–50 msec). Central section of the olivocochlear bundle does not influence this phenomenon.

ISSN:0001-4966    

DOI:10.1121/1.1912597

出版商:Acoustical Society of America    

年代:1971

数据来源: AIP

摘要:

Ten experienced listeners, eight males and two females, whose hearing sensitivity was within normal limits, participated in a study concerned with an assessment of auditory threshold for a 125‐Hz stimulus as a function of stimulus duration and low‐pass filtering of the test stimulus. Thresholds were obtained with a Békésy‐type tracking procedure for six stimulus durations (5, 10, 20, 50, 100, 200 msec) in conjunction with three filtering conditions (unfiltered—UNFIL; 200‐Hz low pass—LP‐200; 150‐Hz low pass—LP‐150). Spectral analysis of the stimuli for each duration and filtering condition was performed. Temporal integration occurred for a 125‐Hz stimulus during the LP‐200 and LP‐150 conditions but not when the stimulus was unfiltered (UNFIL). The LP‐150 condition resulted in an average integration of 11.5 dB/decade between 5 and 200 msec and the average integration for the LP‐200 condition was 8.6 dB/decade. Thresholds over the 5‐ to 200‐msec range for the UNFIL condition did not vary by more than 1 dB, thus indicating the absence of temporal integration. It was inferred that temporal integration occurs for low‐frequency stimuli when the spread of energy toward the higher more sensitive frequency region of the auditory area is limited by low‐pass filtering.

ISSN:0001-4966    

DOI:10.1121/1.1912599

出版商:Acoustical Society of America    

年代:1971

数据来源: AIP

摘要:

Previously published comparisons between behaviorally measured auditory thresholds and cochlear microphonic (CM) sensitivity have not revealed a close correspondence between the two measures. In this study, behavioral data for the cat from Miller, Watson, and Covell (1963) were compared with CM sensitivity for 30 cats. When the data were corrected to account for the altered resonance of the open bulla and the sound‐pressure transformation of the head and auditory meatus of the cat, the two curves were nearly identical in shape. Behavioral threshold, from 0.1 to 20 kHz, is approximately equal to that sound pressure necessary to produce a 0.02‐μV CM output at the round window.

ISSN:0001-4966    

DOI:10.1121/1.1912600

出版商:Acoustical Society of America    

年代:1971

数据来源: AIP

摘要:

Data on the variation in quiet threshold with stimulus duration for tone pulses have been used to examine the validity of an integration model of the ear's behavior. It is found that the ear responds to short‐duration tone pulses in approximately the manner expected of a single time constant integrator, but that there is a significant frequency effect. It is concluded that, within the limits of experimental accuracy, the results can be described either by a reduction in integration time with increasing frequency (from 200 msec at 125 Hz to 100 msec at 10 kHz), or by a constant integration time of 200 msec with a reduction in slope of the integration function as the frequency increases from 125 Hz to 10 kHz.

ISSN:0001-4966    

DOI:10.1121/1.1912601

出版商:Acoustical Society of America    

年代:1971

数据来源: AIP

摘要:

Movements of the basilar membrane and associated cochlear structures give rise to changes in the amount of neural activity measured in first‐order neurons. “Upward” displacements result in increased activity and “downward” displacements in reduced activity. Such changes should be reflected in listening performance as the cochlear duct is moved in the two opposing directions. A detection study designed to investigate differences in audibility resulting from membrane displacement (Deatherage and Henderson, J. Acoust. Soc. Amer.42, 438–440 (1967)] gave results that appeared contrary to these general principles of peripheral transduction. The idea of a 90° phase shift on the basilar membrane and of a time lag between traveling waves are here suggested. These considerations make the psychoacoustic results more compatible with present notions concerning membrane displacement and neural activity.

ISSN:0001-4966    

DOI:10.1121/1.1912602

出版商:Acoustical Society of America    

年代:1971

数据来源: AIP

摘要:

Previous research has demonstrated that a speaker has a high degree of control over his articulatory behavior when asked to repeat sentences several times in exactly the same way. The present research was designed to investigate the use of auditory cues during phonation. Normal‐hearing speakers were instructed to read each of five sentences 25 times in exactly the same manner. While the speakers were talking, a masking noise was presented binaurally through earphones at several sound‐pressure levels (SPLs) (up to 107 dB SPL), which the speakers were instructed to ignore. Measures of peak and integrated intraoral air pressure, SPL, and total phonation time were made to determine the stability of the utterances. Slight increases in SPL, intraoral air pressure, and phonation time accompanied increases in the masker SPL. However, these increases were minimal in comparison to published data suggesting sensory‐motor information other than auditory was utilized by the speakers to control and maintain constant articulatory behavior.

ISSN:0001-4966    

DOI:10.1121/1.1912603

出版商:Acoustical Society of America    

年代:1971

数据来源: AIP

摘要:

As yet, there are no data concerning the regulation of vocal intensity over a range of frequencies in vocal fry phonation. The purpose of this study was to examine changes in vocal intensity and fundamental frequency during vocal fry phonation. Subjects sustained vocal fry for 3 sec at three points in their total vocal fry range and the intensity was recorded. Thereafter, the subjects sustained vocal fry at the three recorded intensities previously obtained and the fundamental frequency recorded. The findings indicated that vocal fry is produced at low intensities in relation to intensity levels noted by previous investigators for the modal and falsetto registers. Furthermore, a dependency between the intensity level and the fundamental frequency of fry phonation for each subject was noted.

ISSN:0001-4966    

DOI:10.1121/1.1912604

出版商:Acoustical Society of America    

年代:1971

数据来源: AIP

摘要:

Additional data are reported on the kinetics of proton‐transfer reactions in aqueous solutions of amino acids to supplement previous work on glycine solutions. Ultrasonic absorption techniques were employed. It is concluded that the data do not satisfy a model based upon independent reactions at the α‐amino and side‐chain amino groups; consequently, some degree of interaction between these sites is deduced but is not quantified.

ISSN:0001-4966    

DOI:10.1121/1.1912605

出版商:Acoustical Society of America    

年代:1971

数据来源: AIP

摘要:

From time to time, strong underwater acoustic signals with frequencies near 20 Hz have been recorded from hydrophones in nearly all oceans. Further details, such as source level, waveform, and movement, are not so well known. These signals may be divided into two main classes: short (∼1 sec) and long (up to 35 sec) emissions of sound at or near 20 Hz. We describe some low‐frequency long signals that were recorded on hydrophones near Midway Island, thus providing a further example of these interesting phenomena. The slow (∼1 knot) meandering of the source, its relatively high signal level (∼70 dBre1 dyn/cm2at 1 yd) and low frequency (23–25 Hz) suggest a large biological source.

ISSN:0001-4966    

DOI:10.1121/1.1912606

出版商:Acoustical Society of America    

年代:1971

数据来源: AIP