摘要:

It is not uncommon to read in speech studies that subjects were instructed to produce speech samples at a ’’comfortable effort level.’’ In many cases the experiments have made the assumption that this level of effort is more or less constant over repeated occurrences. The purpose of this study was to test the constancy of comfortable effort level in speakers’ utterances across experimental sessions. Sixteen speakers were recorded on each of five successive days while producing a series of vowels and phrases. The only instruction to the speakers was to repeat the utterances at a comfortable effort level. Measures of speaking fundamental frequency (SFF) and vocal intensity (SPL) were obtained from the recordings. Results indicate that variability in both SFF and SPL occurred in the utterances; in many cases (especially for SPL) this variability was considerable. These results suggest that experiments desiring constant vocal productions must be more specific in providing instructions to subjects since comfortable effort level can not be assumed to be constant from one experimental session to the next (especially from day to day).Subject Classification: [43]70.40, [43]70.20.

ISSN:0001-4966    

DOI:10.1121/1.381141

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP

摘要:

The purpose of this investigation was to determine if listeners were capable of speaker height and weight identifications from recorded speech samples. A standard prose passage was recorded by 30 speakers, 15 females and 15 males. A master tape containing the randomly arranged recorded readings of all speakers was played to a group of 30 subjects for speaker height and weight identification purposes. All subjects participated in two experimental sessions. In one session they were asked to determine the height of each of the speakers on the tape, and in another session weight judgments were made. The order of presentation of the height and weight tasks was randomized so that 15 subjects made height judgments first while 15 subjects made weight judgments first. A multiple‐choice response sheet containing four choices for the judgment of height and weight for each speaker was provided. Results indicate that the subjects were capable, with slightly better than chance guessing accuracy, of identifying the heights of male and female speakers and the weights of male speakers when presented with only their recorded speech samples. Implications of these findings and suggestions for future research are discussed.Subject Classification: [43]70.30.

ISSN:0001-4966    

DOI:10.1121/1.381142

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP

摘要:

Functional measurement was utilized to study the acoustic cues that contribute to the perception of the voicing difference in /zi/ and /si/. Rather than simply varying the acoustic signal along a single dimension and observing the effect on perception, changes along two acoustic dimensions were covaried in a factorial manner. The time between the onset of the syllable and the onset of vocal‐cord vibration called voice onset time (VOT) was covaried with the fundamental frequency (F0). Observers were asked to indicate where each stimulus fell on a scale from /zi/ to /si/. The results showed that both VOT and F0contribute to the perception of voicing. Sounds were judged as more /zi/‐like with decreases in VOT and with decreases in the F0. The frequency contour of F0during the syllable had very little effect beyond that accounted for by the frequency of F0at the onset of vocal‐cord vibration. Another experiment showed that the role of F0could not be attributed to the possibility that there was less energy at the first formant with higher frequency values of F0. A quantitative model assuming that VOT and F0are perceived independently provided a good description of the observed judgments.Subject Classification: [43]70.30, [43]70.20, [43]70.70.

ISSN:0001-4966    

DOI:10.1121/1.381143

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP

摘要:

Recordings have been made of gelada monkeys freely vocalizing during normal social interchanges in captivity. Spectrographic analyses and perceptual evaluations of the recordings suggest that these primates produce a greater range of vocal distinctive contrasts than have been observed previously. In particular, evidence is presented which suggests that gelada monkeys are capable of producing three distinctive voice qualities, a wide range of vowel qualities, and a set of consonants that differ in manner of articulation (glides, a fricative, plosives, nasals) and in place of articulation (labial, postdental, velar).Subject Classification: [43]70.40, [43]70.20; [43]80.50.

ISSN:0001-4966    

DOI:10.1121/1.381144

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP

摘要:

Measurements of the phases of free jet waves relative to an acoustic excitation, and of the pattern and time phase of the sound pressure produced by the same jet impinging on an edge, provide a consistent model for Stage I frequencies of edge tones and of an organ pipe with identical geometry. Both systems are explained entirely in terms of volume displacement of air by the jet. During edge‐tone oscillation, 180° of phase delay occur on the jet. Peak positive acoustic pressure on a given side of the edge occurs at the instant the jet profile crosses the edge and starts into that side. For the pipe, additional phase shifts occur that depend on the driving points for the jet current, theQof the pipe, and the frequency of oscillation. Introduction of this additional phase shift yields an accurate prediction of the frequencies of a blown pipe and the blowing pressure at which mode jumps will occur.Subject Classification: [43]75.60.

ISSN:0001-4966    

DOI:10.1121/1.381120

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP

摘要:

DUMILOAD (Dummy Mechanical Impedance LOAD) devices have been used to test transducers for many years. In concept the DUMILOAD consists of another specialized piezoelectric transducer mechanically coupled to the transducer to be tested. By varying the electrical impedance placed across the DUMILOAD’s electrical terminals, varying mechanical loads can be presented to the transducer being tested. Drawbacks to this approach have included the need for a cumbersome mechanical coupling device and the limited operating frequency band of the DUMILOAD. This paper describes some of the consideration involved in designing and constructing a DUMILOAD capable of operating at a power level of 1000 W in the frequency band from 3000 to 4000 Hz. Details of a ’’quick connect/disconnect’’ mechanical coupling device are also described.Subject Classification: [43]85.40;[43]30.85

ISSN:0001-4966    

DOI:10.1121/1.381145

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP

摘要:

Measurements of the stress‐induced changes in ultrasonic wave speeds in steels typically used in railroad rails are presented. All of the five possible relative changes in wave speeds for a uniaxial state of stress have been determined and agree, to within the limits of accuracy of the measurement, with the second‐order theory of Hughes and Kelly. The third‐order elastic constants are calculated from the acoustoelastic data.Subject Classification: [43]85.20, [43]85.22, [43]35.26.

ISSN:0001-4966    

DOI:10.1121/1.381146

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP

摘要:

The paper deals with an exact analysis of standing waves in an impedance tube with mean flow. A method is offered for the experimental evaluation of the various wave parameters. Navier–Stokes equations have been solved for evaluating the volume velocity taking into account mean flow, viscosity, etc. The engine exhaust system has been characterized as an acoustic source with an acoustic pressure and internal impedance. A method is suggested for the evaluation of these hypothetical parameters using the exhaust pipe as an impedance tube.Subject Classification: [43]85.20; [43]20.40.

ISSN:0001-4966    

DOI:10.1121/1.381147

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP

摘要:

Experimental evidence is presented which indicates that the coherence of 10 Hz signals in the deep ocean is sufficient to form a passive‐transverse synthetic aperture in excess of 1600 m.Subject Classification: [43]30.20.

ISSN:0001-4966    

DOI:10.1121/1.381148

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP

摘要:

As the bandwidth of a sound increases up to the critical bandwidth, loudness remains constant so long as overall intensity is constant. To keep loudness constant at wider bandwidths, intensity must be reduced. Similarly, the minimum intensity required to activate the acoustic reflex (AR) is constant as bandwidth is increased up to a critical value; beyond that value, intensity can be reduced. This critical width is much wider for the AR than for loudness summation. The literature and some new data show that the difference does not arise simply because the AR is measured at signal levels higher than those at which loudness summation is usually measured. Measured at the same high signal levels as needed to activate the AR, the critical band in loudness summation appears to be about two times wider than at lower levels; the ’’critical bandwidth’’ measured for the AR is some four to six times wider. Moreover, the AR shows a strong dependence on the number of components in a multitone complex, whereas loudness summation does not. Also, at very wide bandwidths the AR threshold shows a much larger decrease than would be predicted by the change in loudness. These differences suggest that the AR is not a direct corollary of loudness.Subject Classification: [43]65.22, [43]65.50, [43]65.75.

ISSN:0001-4966    

DOI:10.1121/1.381118

出版商:Acoustical Society of America    

年代:1976

数据来源: AIP