摘要:

This study investigated the ability of listeners to identify the point where speakers indicated that they shifted from one register to another during phonation. Nine females and 10 males phonated an ascending and descending series of tones, identifying the level at which they perceived a shift between registers. These phonations were recorded and played back to judges, who made the same identifications on a perceptual basis. The results indicated that (1) females were slightly less variable in self‐judgment of their shift between registers than were males and (2) greater variation in register‐shift identification was found for judges listening to the recording than for the speakers' self‐judgments while phonating. It was concluded that registers should be more rigorously defined—perhaps on both a perceptual and physiological basis—in order to account for the difficulty in perceptual identification.

ISSN:0001-4966    

DOI:10.1121/1.1911796

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Acoustic transients resulting from the absorption of normal mode andQ‐switched laser pulses in the mammalian eye have been implicated in damage to retinal tissue. A theoretical analysis indicated that acoustic transients with durations of the same order as the laser pulse (e.g., 100 msec for aQ‐switched pulse) and amplitudes of greater than 100 atm could be produced in model systems that simulate the retina. Piezoelectric transducers and a schlieren optical system were used to verify experimentally the theoretical predictions. By the use of these devices, studies were made of the production of laser‐induced acoustic transients in the rabbit eye. An 18‐mJQ‐switched ruby‐laser pulse produced acoustic transients with amplitudes of 1000 atm in the immediate vicinity of the site of absorption, a 750‐μ‐diam spot on the retina. Normal‐mode laser pulses of the same energy but with durations of 0.5 msec produced a train of pulses with amplitudes 500–1000 times less than theQ‐switched pulse. The biological significance of these findings is discussed.

ISSN:0001-4966    

DOI:10.1121/1.1911797

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Some comments are made with reference to Dr. Hellman's letter.

ISSN:0001-4966    

DOI:10.1121/1.1911798

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Learning is shown to be an important consideration in the articulation testing of frequency‐shifted (mistuned single‐sideband) speech links. Articulation improvements are continuous for up to 100 h of learning, but trade‐offs can be made between subject numbers and training time. System comparison testing is discussed as an efficient alternatives scheme.

ISSN:0001-4966    

DOI:10.1121/1.1911800

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Speech recognition has glamour. Funds have been available. Results have been less glamorous. “When we listen to a person speaking much of what we think we hear is supplied from our memory. [W. James,Talks to Teachers on Psychology and to Students on Some of Life's Ideals(Holt, New York, 1889), p. 159]. General‐purpose speech recognition seems far away Special‐purpose speech recognition is severely limited. It would seem appropriate for people to ask themselves why they are working in the field and what they can expect to accomplish.

ISSN:0001-4966    

DOI:10.1121/1.1911801

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

The serial repetition of 10‐syllable passage that are heard revealed a tendency for the duration of passage and duration of voicing to increase and for the range of pitch and the range of intensity to decrease. The disadvantages of the 10‐syllable nonrhetorical passages are discussed.

ISSN:0001-4966    

DOI:10.1121/1.1911802

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Target strengths of a submerged target, believed to be a sperm whale,Physeter catodon, were measured with the use of a calibrated passive sonobuoy and explosive charges. Measurements of 148 sperm whale echolocation clicks in a13‐octband having a center frequency of 1 kHz resulted in an average source level of 73.5 dB // 1 dyn/cm2with a standard deviation of 3.51 dB.

ISSN:0001-4966    

DOI:10.1121/1.1911803

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

The echolocation signals used by two species of bats,Chilonycteris rubiginosaandEptesicus fuscus, were recorded with four microphones in an array about the bat's head. The bats were trained to broadcast their sounds at a small. Stationary target, and the microphones were arranged in the horizontal plane at angles of 0°, 22.5°, 43°, and 90° with respect to the direction in which the bat pointed its head. The signals produced by both species were directional, with most of the energy projected straight ahead. The sound pressures recorded 22.5° away from the main axis of the broadcasts were about half as great as those recorded from directly in front of each bat.Chilonycterisappears to use a slightly more directional beam thanEptesicus.

ISSN:0001-4966    

DOI:10.1121/1.1911804

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP