摘要:

Intonation can be analyzed, in part, in terms of the phonologic feature breath group. The results of an experiment are discussed in which subglottal air pressure and lung air volume were measured as functions of time for four speakers, in addition to the acoustic signal. These data show that the unmarked or “normal” breath group of American English is characterized at the articulatory level by a relatively steady tension of the laryngeal muscles throughout a single‐bounded expiration of air from the lungs. At the end of phonation, the subglottal air pressure falls and hence the fundamental frequency also decreases repidly. The intonation pattern that is a consequence of this breath group is, of course, the one that has been described as characteristic of declarative sentences and numerous other languages. The marked breath group is differentiated at the articulatory level by an increase in the tension of the laryngeal muscles at the end of phonation, which counteracts the falling subglottal air pressure to produce a not‐falling terminal fundamental frequency contour. The intonation pattern of the marked breath group is the characteristic intonation pattern of the “yes‐no” question in English and other languages.

ISSN:0001-4966    

DOI:10.1121/1.1942683

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP

摘要:

The semicontinuous acoustic signal that we call speech is the result of a number of discrete neuromuscular events. We cannot store in our brain motor commands for every utterance that we may wish to say, owing to the brain's finite storage capacity. Speech then is produced by the rearrangement of a limited number of stored items. What is the size of nature of these stored units? How do speakers encode a sequence of discrete linguistic units into a continuously changing speech signal? An electromyographic study revealed that no simple correspondence exists between a phoneme and its motor commands. Initial and final allophones of consonants differed; both were unaffected by the adjacent vowels. Vowels were influenced by the preceding consonant. The results of this study relevant to the relationship between motor commands and phonetic segments are discussed. Alternative hypotheses relating to the nature of the stored unit are suggested.

ISSN:0001-4966    

DOI:10.1121/1.1942688

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP

摘要:

Electronic‐organ sounds have lacked the “warmth” and beauty of pipes, as reported by Dr. Harvey Fletcher and others. Also, the electronic instruments do not imitate pipe organs sufficiently in sound and operation so that performing artists may be comfortable with and artistically challenged by them. Therefore, electronic‐organ design should begin with analysis of pipe organs. Harmonic analysis was performed on the sound produced by a total of 36 organ pipes from 5 stops. Charts show the average harmonic patterns for each stop and the observed standard deviations. The range of harmonic patterns within each stop was not great enough to destroy its stop identity, although many deviations were aurally detectable. This indicates that each note in a synthetic rank need not, and perhaps should not, have an identical tonal structure. Electronic synthesis of the flute and principal harmonic patterns was approximated through waveshaping and a linear combination of simple waveshapes from octave sources.

ISSN:0001-4966    

DOI:10.1121/1.1942696

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP

摘要:

Investigations of the configurations and motions of the speech‐generating mechanism during an utterance provide data that can be related in a reasonably direct fashion both to the acoustic signal that results from these motions and to the linguistic description that underlies the utterance. Results of several studies of cineradiographic films of speech and of airflow and pressure events in speech show that simple articulatory correlates of the features associated with a given phoneme maintain an identity when the phoneme is embedded in various environments, whereas the acoustic correlates of these features are apparently more complx and are more dependent upon the phonetic environment. Studies of the relations between articulatory activity and the resulting speech sounds can be used to provide insight into the invariant set of acoustic attributes or cues that characterize a given phoneme.

ISSN:0001-4966    

DOI:10.1121/1.1942699

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP

摘要:

When acoustic measurements are made in a shallow lake or tank, reflections from the boundaries produce serious interference in the sound field at frequencies below about 2 kHz. If a dipole (two out‐of‐phase simple sources) is used as a projector, substantial sound‐pressure level is available in the near field, regardless of the well‐known inefficiency of such projectors. At the same time, interference caused by lateral reflection is virtually eliminated by the farfield cosine pattern and that caused by longitudinal reflection is reduced by the inefficiency or low farfield response. Curves show the nearfield sound pressure as a function of dipole size, test distance, boundary geometry, and frequency. Experimental data illustrate elimination of interference in a shallow lake.

ISSN:0001-4966    

DOI:10.1121/1.1942704

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP

摘要:

This paper attempts to explain the observed phenomenon of acoustic reflection from an array of “soft” tubes in an aqueous medium. [W. J. Toulis, J. Acoust. Soc. Am.29, 773(A), 1021–1026, 1027–1033 (1957)] in terms of fundamental array and diffraction theory. Both diffraction and radiation effects are investigated for infinitely long cylindrical tubes of circular cross section as a function ofs/randks. Forks(s/r)−2<1, zero and first‐order diffraction terms together with the corresponding radiation terms suffice. Furthermore, forkr<0.3, the zero‐order radiation term is dominant. Hence, a simple solution for the surface velocity of the typical tube of an infinite array can be found by applying Newton's second and third laws to the tube surface. The infinite series thus obtained bears a strong resemblance to the Fresnel integral. Machine computation is used in a novel way to estimate the sum of this series.

ISSN:0001-4966    

DOI:10.1121/1.1942711

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP

摘要:

A review of recent work in our laboratory, including techniques and experimental results on water, alcohols, and acetates to about 10 000 atm pressure. The interpretation of these data in terms of molecular relaxation processes is discussed.

ISSN:0001-4966    

DOI:10.1121/1.1942714

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP

摘要:

The cochlear potentials for the kangaroo rat display an unusual sensitivity to the low frequencies. This animal also possesses extremely large bullae to which some investigators have attributed enhancement of low‐frequency tones. Attempts to reveal the function of these bullae by electrophysiological measures are discussed.

ISSN:0001-4966    

DOI:10.1121/1.1942721

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP

摘要:

Activity of single cells in cats immobilized with gallamine triethiodide was recorded with metal microelectrodes and displayed by an on‐line dot display. Tone‐burst, noise‐burst, click, and swept‐tone stimuli were presented through condenser microphones at both ears. Spontaneous activity ranged from less than one spike per second to greater than 40 spikes per second. Almost all cells were affected by acoustic stimuli, either by enhancement of activity, reduction of activity, or a combination. Cells were affected at the onset and/or termination of a stimulus, throughout a stimulus, or a combination. Best frequency of cells ranged from less than 1 kHz to greater than 50 kHz. The pattern of response to tone bursts of some cells changed as the frequency of the stimulus was changed. The activity of some cells was closely related to the slow‐wave potential at the electrode tip, but for others there was little relationship. Subsurgical doses of sodium pentobarbital greatly reduced both spontaneous and evoked unit activity. [Work supported in part by the Public Health Service, U. S. Department of Health, Education, and Welfare, and by the U. S. Air Force Office of Scientific Research.]

ISSN:0001-4966    

DOI:10.1121/1.1942725

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP

摘要:

Rapid growth in the capability and availability of high‐speed electronic computers has stimulated interest in methods for the analysis of acoustic radiation from bodies of arbitrary shape. Either a differential or integral formulation of these acoustic radiation problems provides a basis for the numerical methods discussed in this survey. Various discrete approximations can be applied to either formulation to produce a system of linear algebraic equations. Because this system of equations is usually very large, it is necessary to make use of the special properties of the system in order to obtain a solution economically. Recently‐developed techniques for constructing and solving these equations in typical problems are reviewed. It is also shown that these numerical methods can be extended to mixed boundary‐value problems with little additional complexity.

ISSN:0001-4966    

DOI:10.1121/1.1942730

出版商:Acoustical Society of America    

年代:1966

数据来源: AIP