摘要:

This report tests the hypothesis that individual humpback whales (Megapteranovaeangliae) can be recognized and discriminated from other individuals on the basis of the ’’cry’’ vocalization. Multivariate discriminant analyses, based on six measurable variables, were used to examine intra‐ and interindividual differences in the ’’cries’’ from several individuals. Cries between themes of one song are very different, whereas those between songs of one individual are similar. Results show a high degree of discriminating power between individual animals. Thus, signature information is potentially available from ’’cries’’ within songs, despite common song formats for all calling animals on a given bank. The statistical techniques used will be of great value in animal vocalization studies.

ISSN:0001-4966    

DOI:10.1121/1.383072

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP

摘要:

In nests ofVespaorientalis, sounds are produced both by the larvae (hunger signal) and the adults. Adult workers mainly produce solid borne sounds by tapping the abdomen tip against the rim of the comb. Among these distinct series of tapping sounds is that produced by one or several workers facing the queen as she rests between oviposition sessions. Statistical analysis of 25 series of such taps shows that consecutive taps in a given series tend to be associated in one of the following combinations: (a) much frequency autoassociation, and little amplitude autoassociation; (b) much amplitude autoassociation. It seems that in (a), the tapping is executed in a manner resembling radio frequency modulation (FM), while in (b) it resembles radio amplitude modulation (AM).

ISSN:0001-4966    

DOI:10.1121/1.382975

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP

摘要:

A four‐alternative, forced choice adaptive procedure was used to measure the lowest intensity at which children could identify monosyllabic nouns that had been standardized to be understandable (at comfortable listening levels) to inner city, 3‐year‐old children. Results showed no age‐related performance changes when the words were presented against a 12‐talker babble or against filtered noise. In quiet, however, performance improved between the ages of 5 and 10 years. Performance of children with learning problems was poorer than performance of children achieving normal school progress, even though clinical measures of auditory sensitivity showed no differences. Results are discussed in terms of ’’semantic closure’’ skills of children.

ISSN:0001-4966    

DOI:10.1121/1.383065

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP

摘要:

The effects of small room reverberation (T=0.8 s) upon phoneme recognition was studied for normal listeners. Recognition performance was significantly poorer under reverberation than in quiet, and poorer in the final position of words than initially. Relative information transmission under reverberation was poorest for place of articulation, and for stop and frication consonants; whereas sibilance, duration, and semivowel information were barely affected. The findings suggest that small room reverberation affects phoneme recognition in much the same way as a speech‐shaped masking noise. In some cases, the error distributions reflect the limited response alternatives imposed by the real word recognition test.

ISSN:0001-4966    

DOI:10.1121/1.383075

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP

摘要:

Important issues in selective adaptation research concern the relative contribution of response related (perceptual) and stimulus related (acoustic) effects of the adaptor in the adaptive process. Two response related issues pertain to the effects of the adaptor percept and verbal transformations on adaptation. This investigation systematically examined perceptual and acoustic contributions of the adaptor on the adaptation of the voicing feature. Subjects rated the degree of voicing/voicelessness of end‐point VOT adaptors, i.e., 5‐ and 55‐ms VOT, and an acoustically neutral adaptor, i.e., 25‐ms VOT, during periods of repetitions. The number of adaptor repetitions during each of ten trials was either 5, 32, or 95, and the intensity of the adapting stimulus was either 50, 70, or 90 dB SPL. The major findings were as follows: (1) No significant correlations were found between ratings of voicing percept of the adaptor and magnitude of boundary shift; (2) Increases in repetitions and relative intensity level of end‐point adaptors produced significantly greater phonetic boundary shifts and generally greater affects on ratings of test stimuli; and (3) The end‐point adaptors produced significant shifts in rating of boundary and nonboundary stimuli. The findings indicate that neither the adaptor percept or verbal transformations affected the magnitude of adaptation. These results and those for acoustic parameters strongly suggest an acoustic as opposed to a phonetic basis of adaptation of the voicing feature. Furthermore, the effects of end‐point adaptors on boundary and nonboundary stimuli support the generalized change in feature sensitivity assumed by a fatigue model of adaptation.

ISSN:0001-4966    

DOI:10.1121/1.383034

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP

摘要:

The utility of phonetic features versus acoustic properties for describing perceptual relations among speech sounds was evaluated with a multidimensional scaling analysis of Miller and Nicely’s [J. Acoust. Soc. Am. 27, 338–352 (1955)] consonant confusions data. Theindscalmethod and program were employed with the original data log transformed to enhance consistency with the linearindscalmodel. A four‐dimensional solution accounted for 69% of the variance and was best characterized in terms of acoustic properties of the speech signal, viz., temporal relationship of periodicity and burst onset, shape of voiced first formant transition, shape of voiced second formant transition, and amount of initial spectral dispersion, rather than in terms of phonetic features. The amplitude and spectral location of acoustic energy specifying each perceptual dimension were found to determine a dimension’s perceptual effect as the signal was degraded by masking noise and bandpass filtering. Consequently, the perceptual bases of identification confusions between pairs of syllables were characterized in terms of the shared acoustic properties which remained salient in the degraded speech. Implications of these findings for feature‐based accounts of perceptual relationships between phonemes are considered.

ISSN:0001-4966    

DOI:10.1121/1.382972

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP

摘要:

Simulation of glottal volume flow and vocal fold tissue movement was accomplished by numerical solution of a time‐dependent boundary value problem, in which nonuniform, orthotropic, linear, incompressible vocal fold tissue media were surrounded by irregularly shaped boundaries, which were either fixed or subject to aerodynamic stresses. Spatial nonuniformity of the tissues was of the layered type, including a mucosal layer, a ligamental layer, and muscular layers. Orthotropy was required to stabilized the vocal folds longitudinally and to accomodate large variations in muscular stress. Incompressibility and vertical motions at the golttis played an important role in producing and sustaining phonation. A nominal configuration for male fundamental speaking pitches was selected, and the regulation of fundamental frequency, intensity, average volume flow, and vocal efficiency was investigated in terms of variations around this nominal configuration. Parameters which were varied consisted of geometrical factors such as length, thickness, and depth, factors for shaping the glottis, as well as tissue elasticities, tissue viscosities, and subglottal pressure. Since nonlinear stress–strain properties were not included, subglottal pressure did not produce a pronounced effect upon fundamental frequency under these somewhat idealized conditions.F0rasing correlated strongly with increased tension in the ligament, and somewhat with increasing tension in the vocalis.F0lowering correlated with increase in vocal fold length when the tensions were held constant, but not with increase in vocal fold thickness. Vocal intensity and efficiency are shown to have local maxima as the configurational parameters are varied one at a time. It appears that oral acoustic power output and vocal efficiency can be maximized by proper adjustments of longitudinal tension of nonmuscular (mucosal and ligamental) tissue layers in relation to muscular layers. Quantitative verification of the ’’body‐cover’’ theory is therefore suggested, and several further implications with regard to control of the human larynx are considered.

ISSN:0001-4966    

DOI:10.1121/1.382973

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP

摘要:

A new method was employed to measure the changes in the strength of ear dominance in the perception of dichotic chords as a function of stimulus intensity. The results of the first experiment, where the right and left tones were of equal intensity, revealed striking individual differences in the way the ear dominance of five subjects changed as the intensity of the chords was varied over a 60–dB range—no two subjects exhibiting the same pattern of behavior. Since, within the context of the model of Yund and Efron [J. Acoust. Soc. Am. 62, 607–617 (1977)] these individual differences could result from right–left asymmetries in the subject’s intensity‐response (I‐R) transduction mechanisms, a second experiment was performed in which the two tones had different intensities. From the results of the second experiment the shape of the I‐R function for each ear could be computed. Using these I‐R functions as parameters, the model accurately predicted the idiosyncratic changes of ear dominance observed in the first experiment. The right‐left asymmetries in the I‐R functions also account for previously reported idiosyncratic changes in ear dominance as a function of the frequency difference between the two tones of the dichotic chord.

ISSN:0001-4966    

DOI:10.1121/1.382974

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP

摘要:

Most studies of the musical pitch of harmonic tone complexes have utilized signals comprising two or more successive harmonics. The present study provides systematic data on melodic interval recognition by three musically experienced subjects with sounds whose missing fundamentals were represented by two nonsuccessive harmonicsnf0,(n+m)f0, delivered to separate ears. Data were obtained in the ranges 1?n?9, 2?m?4, and 200 Hz ?f0?1000 Hz. The data are interpreted in the light of three theories, the ’’optimum processor theory,’’ the ’’virtual pitch theory,’’ and the ’’pattern transformation theory.’’ For each theory, a constraint on performance is proposed based on interference between the ’’analytic’’ and ’’synthetic’’ pitch perception modes. The former is obtained with large spacings between harmonics, where listeners are more likely to perceive harmonics as individual tones, each having their own pitch. This degrades the listener’s ability to hear the fundamental pitch.

ISSN:0001-4966    

DOI:10.1121/1.382943

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP

摘要:

A monaural complex tone is synthesized from 12 harmonically related pure tones, played in phase. In each of 12 segments, one of the tones (thetarget) is played out of phase so that the sequence of targets is increasing or decreasing in frequency. If the target is at least 30° out of phase, the targets are perceptually segregated. This tone‐segregation by phase raises doubts concerning several current theories of pitch perception. The phenomenon is conjectured to be caused by the ear’s nonlinear compressive transfer characteristic or by a temporal analysis of the stimulus.

ISSN:0001-4966    

DOI:10.1121/1.383061

出版商:Acoustical Society of America    

年代:1979

数据来源: AIP