摘要:

In a series of experiments, evidence was obtained for phonemic restoration when a word with the segment /s/ excised and replaced by silence and a comparable noise segment were presented dichotically. What has been called phonemic integration was also demonstrated by presenting the excised /s/ and the word with the /s/ removed and replaced by silence dichotically. Phonemic restoration and integration effects tended to be enhanced when barely audible versions of the excised /s/ or noise segment replaced the silence. Finally, phonemic integration was obtained when words with an excised CV syllable or VC rime were presented dichotically together with the remainder of the word.

ISSN:0001-4966    

DOI:10.1121/1.414598

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP

摘要:

Using synthetic speech, word duration and fundamental frequency (F0) contours were parametrically manipulated to examine processes of phrasal interpretation by adult and child (5 and 7 years old) listeners. From an adult male voice, versions of the phrase ‘‘pink and green and white’’ were resynthesized to produce stimuli suggesting two possible interpretations: [(pink and green) and white] and [pink and (green and white)]. For each stimulus, listeners pointed to a picture to indicate which interpretation was intended. All subjects used duration and (to a lesser extent) intonation as perceptually salient cues for phrasal interpretation. The manner in which subjects processed this information was evaluated by comparing subjects’ performance with the predictions of three different information processing models: a nonindependent cue‐evaluation model, and two independent cue‐evaluation models (an additive model, and the multiplicative, fuzzy logical model). Performance was best described by the fuzzy logical model, which assumes independent cue evaluation and generates a classification function characterized by cue trading relations. The results suggest that, similar to adults, children as young as 5 years of age rely on acoustic‐prosodic information for syntactic phrase interpretation, and they process this information in an adultlike manner.

ISSN:0001-4966    

DOI:10.1121/1.414599

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP

摘要:

This study assessed the influence of subjective lexical familiarity and English‐language experience on Japanese adults’ accuracy in identifying singleton word‐initial tokens of English /ɹ/ and /l/. The inexperienced Japanese (IJ) subjects had lived in the U.S. for 2 years, whereas the experienced Japanese (EJ) subjects had lived there for 21 years, on average. The native Japanese subjects correctly identified English /in r/ and /l/ tokens less often than did a group of native English (NE) subjects, but they did not differ from the NE subjects in identifying the control consonants /w/ and /d/. The NE subjects, who were at ceiling, showed no effect of subjective lexical familiarity. However, the EJ and IJ subjects correctly identified /in r/ and /l/ tokens more often in words that were more familiar than their minimal pairs than in words that werelessfamiliar than their minimal pairs. The EJ subjects identified liquids more often than did the IJ subjects, but usually less often than the NE subjects. However, the EJ subjects managed to identify /in r/ tokens at rates comparable to the NE subjects’ rates in words that were matched in subjective familiarity to their minimal pair (experiment 1), and when identifying /in r/ tokens that had been edited out of their original word or nonword context (experiment 2).

ISSN:0001-4966    

DOI:10.1121/1.414884

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP

摘要:

Patients who use the Ineraid cochlear implant were tested in four experiments with materials which assessed frequency discrimination and speech understanding. In each experiment both frequency discrimination and speech recognition varied among patients. Correlations between the two measures were significant and ranged from 0.60 to 0.83. Most generally, frequency discrimination was better in the frequency domain ofF1 than in the domain ofF2. In experiment 5, both the Ineraid signal processing strategy and a continuous interleaved sampling (CIS) strategy were implemented for a single patient. The CIS strategy improved frequency discrimination in the domain ofF2 and improved speech understanding.

ISSN:0001-4966    

DOI:10.1121/1.414600

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP

摘要:

An algorithm for detection of vowel onsets in fluent speech was presented by Hermes [J. Acoust. Soc. Am.87, 866–873 (1990)]. Performance tests showed that detection was good for fluent speech, although the parameter settings had to be modified for application to well‐articulated speech. One of the purposes of the algorithm was application to speech by deaf persons, for which it failed completely. In order to improve the algorithm and to make it more generally applicable, two alternative detection strategies have been explored in the present study. These strategies were (a) simulation of transient‐chopper responses in the cochlear nucleus and (b) training of multilayer perceptrons. Two large databases of read speech have been used for performance comparison of the original algorithm and the new strategies. The strategy based on simulating cochlear‐nucleus responses is found both to result in a higher false‐alarm rate than the original algorithm and to be rather level dependent. On the other hand, the performance of a multilayer‐perceptron network, trained on mel‐scaled spectra, is comparable to the performance of the Hermes algorithm. In more general terms, the results suggest that temporal information on intensity and (rough) spectral envelope are important for human vowel‐onset detection behavior. Information on harmonicity can be used as a secondary source of information to avoid detection of mainly unvoiced, nonvowel onsets.

ISSN:0001-4966    

DOI:10.1121/1.414671

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP

摘要:

Trumpet sound simulation is carried out with a two‐dimensional lip vibration model, where the lips execute both swinging and stretching motions. This model allows lips to operate on both the lower and higher frequency sides of the air‐column resonance frequencies. Oscillations generated by the total sound production system are on both the lower and higher frequency sides in the first through third resonance modes, while in the fourth and higher modes they are realized only on the lower side. From each resonance mode, an oscillation having the least frequency deviation against a change in lip eigenfrequency and also having sufficient amplitude is selected as the optimum oscillation of the resonance mode. It is found that these oscillations in the lower modes have positive phase differences between lip vibration and mouthpiece pressure, whereas those in the higher modes have negative ones. This result closely matches the transition of lip vibration states from the one modeled by the outward‐striking valve at the second mode (i.e., the lowest mode among those used musically) to that modeled by the laterally striking valve at the higher modes, which is observed in the simultaneous measurement of mouthpiece pressure and lip vibration.

ISSN:0001-4966    

DOI:10.1121/1.414601

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP

摘要:

A recently developed high resolution frequency tracker [J. C. Brown and M. S. Puckette, ‘‘A high resolution fundamental frequency determination based on phase changes of the fourier transform,’’ J. Acoust. Soc. Am.94, 662–667 (1993)] has made it possible to measure the ratios of the frequencies of the upper harmonics of a sound with respect to its fundamental frequency with high accuracy. Calculations were carried out on digitized sounds produced by a clarinet, alto flute, voice, piano, violin, viola, and cello. The sounds produced by the stringed instruments included examples played pizzicato and bowed both with and without vibrato. Measured ratios were exactly equal to integers for all instruments except the piano and strings played pizzicato. Anomalous behavior was observed for the fundamental frequency for vibrato sounds played by stringed instruments with the frequency deviation exceeding the extrema of the other harmonics divided by their harmonic number by about 1% on average. Piano inharmonicity was proportional to harmonic number squared in agreement with Fletcher [J. Acoust. Soc. Am.36, 203–209 (1964)]. The major limitation on this calculation was found to be instrumental fluctuations.

ISSN:0001-4966    

DOI:10.1121/1.414602

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP

摘要:

The purpose of the present study was to obtain detailed photographic sequences and lip motion data on which lip models for brass instruments may be more accurately based. The study expands upon an earlier study by Martin [J. Acoust. Soc. Am.13, 305–307 (1942)] by using advanced fiber‐optic stroboscopy, a real instrument mouthpiece, and by studying two dynamic levels. The trombone was selected as representative of the brass family because its relatively large mouthpiece permitted the use of an optic probe. Lip motion was observed from the front and side for six notes (Bflat2, F3, Bflat3, D4, F4, Aflat4) played at loud and soft dynamic levels. The video sequences were used to obtain information on lip opening area, lip motion perpendicular to airflow, and lip motion parallel to airflow. The data are tabulated and represented in graphic form.

ISSN:0001-4966    

DOI:10.1121/1.414603

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP

摘要:

Reed instruments have been categorized into two families since Helmholtz: the ‘‘striking inward’’ and the ‘‘striking outward’’ reeds. In an attempt to clarify the question to which family the lips of the brass player belong, a Helmholtz resonator with active feedback was used as a single‐mode brass instrument and the playing frequencies generated by three trumpet players were measured. By adjusting the gain and the phase in the feedback loop, the resonant frequency and the quality factor of the resonator can be varied. The acoustic impedance at the mouthpiece is measured by a novel method without removing the player’s lips. The results show that with extreme efforts the players can generate playing frequencies both lower and higher than the corresponding air column resonance, but that the playing frequency under normal playing conditions (the ‘‘most comfortable note’’) is almost always higher than the corresponding air column resonance. This supports the view that human lips function as ‘‘striking outward’’ reeds.

ISSN:0001-4966    

DOI:10.1121/1.414604

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP

摘要:

An important consideration in the use of ultrasound in biomedical applications is controlling the range and spatial resolution. In this study, the feasibility of using a mechanical waveguide to control the axial range of a flat disk transducer is considered. The waveguide is a water‐filled, circular glass cone fixed to the transducer. Experimental beam measurements are compared to theoretical predictions for transducers with and without waveguides. The results confirm that mechanical waveguides may be used to control the axial location of the natural focus and reduce the beamwidth at the focus and beyond. They provide a relatively inexpensive alternative to phased arrays and more flexibility than single‐element transducers, as different sized waveguides would allow a single transducer to operate at a variety of axial ranges and spatial resolutions.

ISSN:0001-4966    

DOI:10.1121/1.414605

出版商:Acoustical Society of America    

年代:1996

数据来源: AIP