摘要:

Two‐sound sequences with interpulse intervals of312 secwere presented to subjects in order to evaluate the character of judgments involved in temporal comparisons of the successive sounds. A 1000‐Hz tone and wide‐band noise were presented in all possible two‐sound combinations. The duration of the first (referent) sound was 500 msec, and the duration of the second (comparison) sound ranged from 300 to 700 msec. The subjects' task was to state whether the second sound was shorter, of the same duration, or longer than the first sound. As the difference in the durations of the two sounds increased, accuracy of judgments improved. The effect was asymmetrical; judgments were more accurate when the second sound was shorter than the first sound and less accurate when the second sound was longer, given equivalent differences in duration. Subjective impressions were that noise bursts were longer than tone presentations of the same duration, which accords with the finding that the asymmetry in accuracy of judgments was diminished by tone‐noise combinations and enhanced by noise‐tone combinations.

ISSN:0001-4966    

DOI:10.1121/1.2016066

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

Hemispherectomized subjects display a strong ear dominance for the pitch mixture of dichotic chords: The tone presented to the ear ipsilateral to the removed hemisphere is less salient in the dichotic sound image than is the contralateral ear tone [R. Efron, M. Dennis, and J. E. Bogen, J. Acoust. Soc. Am.60, Suppl. No. 1, 550 (1976)]. Two possible causes for similar ear dominance seen in normal subjects are an asymmetry in the transducer properties of the two ears or an asymmetry in the way two basically symmetrical inputs are combined centrally [E.W. Yund and R. Efron, J. Acoust. Soc.62, 607–617 (1977)]. Evidence for the former derives from the finding that the dominant ear tends to have a superior frequency resolving capacity [P.L. Divenyi, R. Efron, and E.W. Yund, J. Acoust. Soc. Am.62624–632 (1977)]. Evidence for the latter derives from the present experiments which show that, in hemispherectomized subjects, there is no difference between the frequency dl in the two ears. The results suggest the existence of an efferent pathway from the cortex which can influence the way pitch information from the two ears is combined (weighted). [Work supported by the Veterans Administration.]

ISSN:0001-4966    

DOI:10.1121/1.2016120

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

Eight CV's (with a) were audio/video color recorded. The consonants included p, b, k, g, s, z, f, and v. Using video‐editing techniques the audio from these consonants was dubbed such that all possible pairings of each visual consonant occurred with each audio consonant. Thus 64 stimuli were constructed that consisted of 56 conflicting visual and auditory stimuli and eight nonconflicting stimuli. Subjects were seated in front of a video monitor with earphones and asked to write their response to each stimulus item. The auditory‐alone mode confirmed unequivocally correct intelligibility of each consonant. However, when conflicting visual speech reading cues were present confusions were reliable and consistent. Confusions within the fricative class (f, v, s, and z) occurred as well as confusions within the stop class (p, b, k, and g). Interclass confusions were also prominent. Especially noteworthy was the perception of consonants not present acoustically (e.g., θ, Ø, t, 1). An extremely robust confusion occurred for (f) presented visually and (b) auditorily. With voicing present auditorily subjects responses were consistently a voiceless (f). These data will be discussed with respect to distinctive feature theory and information processing.

ISSN:0001-4966    

DOI:10.1121/1.2016172

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

An experiment was performed to find out how well human listeners could determine whether or not two different utterances were spoken by the same speaker. The speech was coded in three ways: high‐quality PCM (natural speech), linear prediction encoding (LPC), and ADPCM at 24 kbps. For this experiment all combinations of these three coding methods were used. A group of 16 reference speakers (customers—8 males, 8 females) along with 78 test speakers (16 reference and 62 imposters) were used in the experiment. Two test utterances were used: one for the male speakers and one for the female speakers. The 30 naive listeners who participated in the experiment were required to make same/different judgments. The results will be discussed in terms of the imposter acceptance error rates (miss rates) and customer rejection error rates (false‐alarm rates) for the different test conditions.

ISSN:0001-4966    

DOI:10.1121/1.2016225

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

The purpose of this study was to determine if measures of speaking fundamental frequency and its perturbation, as well as selected durational aspects of speech may be used to discriminate normal from abnormal phonation, specifically, in five pairs of talkers matched for age. A spoken sentence and sustained /a/ provided the sample for the acoustic analyses. Fifty glottal waveforms from each subject were measured to determine the mean perturbation of the fundamental frequency for the sustained vowel. The best predictor variables for these subjects from the seven variables analyzed were found to be the vocalic duration of the sentence segment and the mean perturbation for sustained vowels.

ISSN:0001-4966    

DOI:10.1121/1.2016284

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

Recordings of phrases and sentences, contrasting on the prosodic level, were obtained from normal‐hearing and hearing‐impaired children, 9–12 years of age. Preliminary results from an acoustic analysis ofF0, durational, and intensity patterns indicate that, on questions, the normal‐hearing children make use of the typical risingF0contour, although not always on the appropriate syllable. Also, the slope of the risingF0contour is not as consistent as was found for English adults [Ashby, Proc. Eighth Int. Congr. Phonet. Sci. (1975)l. The hearing‐impaired children exhibited some control over prosodic pattern features, but these were not systematically appropriate. In particular, they appeared to use idiosyncratic durational cues contrastively between question and statement. One hypothesis is that durational cues compensate for the inability to reproduce the cause (F0rise) of a perceived consequential acoustic change (increased intensity). This does not necessarily signal “deviant” language behavior since normal‐hearing children go through similar stages at earlier ages. [Research supported in part by PHS Grant No. 09252 from NINCDS.]

ISSN:0001-4966    

DOI:10.1121/1.2016335

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

Montgomery County, an affluent, suburban, and rural county neighboring Washington, DC, has received numerous noise complaints before and after the Noise Control Ordinance became effective (October 1976). A program was initiated to develop an approach to categorize and analyze citizen complaints so that a broad rational statement as to the effectiveness of the ordinance could be made. This paper presents only a part of the results of the program that was developed to analyze the effectiveness of the ordinance and deals only with noise problems that were serious enough to lead to “official” complaints by the citizens. All complaints were tabulated into categories that include the type and location of complaints, the action taken, and the long‐term effects of the action. Complaints are plotted as a function of various parameters to show the factors influencing complaints. The analysis will be updated and refined periodically.

ISSN:0001-4966    

DOI:10.1121/1.2016391

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

One group of subjects was trained to rate the loudness of tape‐recorded sounds on a decibel‐type scale, while another group learned to rate the same sounds on a sone‐type scale. In a pretest, subjects wrote magnitude estimates of 30 sounds. During training, subjects heard 60 sounds, each accompanied by the display of a placard giving the scale value. In the post‐test, subjects listened to another 30 sounds and wrote their estimates for the scale values which they had just learned. The 6‐sec sound samples were selected from 27 different spectra (both artificial and environmental) and ranged from 60 to 100 dB on theA‐weighted scale. They were presented simultaneously over loudspeakers in identical lecture rooms for each group. In the pretest the mean correlation coefficient for the decibel group was 0.72 (26 subjects) while the mean correlation for the sone group was 0.65 (26 subjects). In the post‐test the mean correlations were 0.88 and 0.85 for the two groups, respectively. Thus, although a sone‐type scale supposedly reflects subjective ratio relationships, it was not easier to learn than a decibel‐type scale.

ISSN:0001-4966    

DOI:10.1121/1.2016442

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

Virtually all of the variance in data on the extent of urban noise‐induced annoyance in 24 American communities was predictable by stepwise regression from speech‐interference information. Both the annoyance and speech‐interference data were collected in the course of a National Urban Noise Survey, an EPA‐sponsored study intended to examine response to non‐aircraft, nonhighway noise in communities of widely varying exposure levels, population densities, and geographic areas. Neither complaint rates nor demographic factors alone were found to be usefully predictive of the extent of community annoyance.

ISSN:0001-4966    

DOI:10.1121/1.2016496

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

In 1972 at the 84th meeting of ASA, a similarly titled review paper was presented by this author. Since that time, the field has progressed from very early beginnings and speculations to the point where there now appears to be some well‐defined applications and advantages of the technique. In addition, a scanning laser acoustic microscope (SLAM) has become available commercially. Placed in the hands of biomedical and materials scientists, the SLAM becomes an important analytical tool for revealing aspects of microstructure which are not obtainable by optical or electron microscopes. In particular, the varying elastic properties of materials, e.g., compressibility and density, at the microscopic‐size level are sensitive parameters upon which to differentiate structure. Applications of the SLAM to materials science, nondestructive testing, and biomedical research will be examined.

ISSN:0001-4966    

DOI:10.1121/1.2016017

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP