摘要:

The paper will describe a 600 statementFORTRAN IVsubprogram for the synthesis‐by‐rule of simple statements in Serbo‐Croatian, a Slavic tone language. The model receives an input phoneme string, calculates the duration of each segment in the string, computes a set of fundamental frequency values corresponding to the sentence intonation, and then modifies these fundamental frequency values to reflect the influence of word tone. Several factors affect the calculation of segmental duration, e.g., number of segments in the string, number of syllables in the word, accented versus unaccented syllable, type of accent, voicing characteristics of adjacent consonants, and others. Word tone is calculated as a deviation from the previously defined sentence intonation. The paper will be accompanied by slides and tape‐recorded samples.

ISSN:0001-4966    

DOI:10.1121/1.1982569

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP

摘要:

A method has been developed to provide plane‐wave operation in the Mark III pressure gradient hydrophone calibrator [Wide Range Calibration System for Pressure Gradient Hydrophones, B. B. Bauer, L. A. Abbagnaro, and J. Schumann, J. Acoust. Soc. Amer.51, 1717 (1972)]. Since this calibrator uses a mechanical drive rather than a transducer drive to establish the standing wave field, conventional time delay techniques could not be employed. Rather, two loudspeakers were used in conjunction with the calibrator drive to achieve a plane wave at the center of the tank. A simple operating procedure is described for using the plane‐wave mode, and some experimental results are presented.

ISSN:0001-4966    

DOI:10.1121/1.1982571

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP

摘要:

The self and mutual acoustic radiation impedances for two coplanar unbaffled disks are calculated using an eigenfunction expansion in terms of oblate spheroidal wave functions. Terms representing outgoing waves from both disks are included. One disk is assumed to be vibrating with a rotationally symmetrical normal velocity distribution, and the other disk is assumed to be stationary. The determination of the expansion coefficients from these boundary conditions is facilitated by the use of an addition theorem which expresses spheroidal wave functions with reference to one coordinate frame in terms of spheroidal wave functions with reference to a second coordinate frame. Numerical results for the special cases where the vibrating disk is either oscillating uniformly or vibrating uniformly on only one side are presented and discussed.

ISSN:0001-4966    

DOI:10.1121/1.1982581

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP

摘要:

Environmental noise at the property line due to an industrial operation is one element that determines the minimum site area requirements for a new plant. Residents in communities surrounding a plant hear the noise created within the plant that is attenuated by the building and the size of the buffer zone between the plant and the community. In suburban and rural areas where the ambient background noise may be low, sites for heavy industry plants become exceedingly large if insulated metal type siding is used for the building walls to achieve a satisfactory sound level at the property line. When large sites are not available, or if the price of land is high, the site area can be considerably reduced by the use of masonry or multilayered insulated metal types of siding. For a plant with an interior noise level of 90 dBA, the site area for a plant with masonry siding may be less than 10% of the site area for the same plant with insulated metal siding. The use of high sound transmission loss walls for plant buildings necessitates that noise from other sources such as fans, ventilating system, steam vents, etc., be reduced to meet the property line sound criterion. This paper presents a graphical method for estimating plant site area and setback requirements based upon maximum allowable property line noise levels, plant noise levels, and type of building siding selected for the construction. In addition, a method is proposed for determining the economic break‐even point for purchasing additional property as an acoustical buffer zone versus the cost of improving the sound transmission loss of the building siding.

ISSN:0001-4966    

DOI:10.1121/1.1982586

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP

摘要:

Board vibration has been identified as the dominant noise generating mechanism for a majority of wood planers. The effectiveness of compact enclosures is greatly diminished owing to board vibration, since a portion of boards of normal stock length is always outside of the enclosure. A vibration suppression system has been designed to operate inside of an enclosure to reduce the amount of vibratory energy transmitted outside through the boards being machined. The system developed and its effectiveness in reducing wood planer noise when used in conjunction with a compact enclosure is described in detail. [Newman Machine Company and NASA are acknowledged for support of this work.]

ISSN:0001-4966    

DOI:10.1121/1.1982592

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP

摘要:

Binaural intensity functions for cells in the posterior colliculus can vary in slope and sensitivity depending upon the phase relations of the stimuli at the two ears. Interaural phase differences that produced low and high discharge rates were chosen as locations on a cell's phase function at which to examine its response to binaural intensity. The inhibitory or excitatory effect of phase angle is maintained across a wide range of intensity.

ISSN:0001-4966    

DOI:10.1121/1.1982598

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP

摘要:

The effect of intensity tipon the amplitude of the cortical potential evoked by electrical stimulation of the contralateral VIIIth nerve in an anesthetized guinea pig was studied. Square pulses, 0.5 msec in duration, were delivered through stainless‐steel electrodes implanted in the VIIIth nerve. The stimulus intensity was randomly varied and the amplitude of the cortical potential was measured from a storage oscilloscope in a double blind manner. The amplitude at first rose sharply and then plateaued as the current intensity was further increased. The intensity function for electrical stimulation was different from that usually observed for acoustical stimulation in two respect. (1) For similar increases in stimulus intensity, a greater increase in the amplitude of the evoked potential was observed with electrical stimulation than with acoustical stimulation. This suggests the use of loud sound in behavioral transfer tests between acoustical and electrical stimulation of auditory centers. (2) Increases of stimulus intensity beyond that needed to produce plateau levels caused a reduction in the evoked potential amplitude with acoustical stimulation, but no reduction was observed with eleetrical stimulation. These data suggest that the reduction observed at high intensities of acoustical stimulation is due to a cochlear process, most probably the cochlear microphonic. [Supported in part by the National Institute of Neurological Diseases and Stroke and the Deafness Research Foundation.]

ISSN:0001-4966    

DOI:10.1121/1.1982604

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP

摘要:

Human event related potentials (ERP) were taken using averaging techniques to tonal pulses with systematically varied onset ramp. The rate at which the tonal pulse grows to full amplitude (ramp) was linear on both signal onset and offset. Auditory evoked potentials (AEP), were taken on seven naive college sophomores, with demonstrated normal hearing (ISO, 1964), for onset ramps of 50, 150, 500, 1500, and 5000 msec and a no‐signal condition. Offset was 50 msec for all signal conditions. Equipment, calibiation, between‐subject variation, and noise considerations required that 64 trials be averaged to achieve useful (approx. 8:1) SIN ratios. Trials consisted of 5.05‐sec signal condition to 45‐dB sensation level full amplitude and 9.95‐sec intertrial interval. Visual analyses indicate that onset ramp affects offset AEP progressively less for all signal conditions as ramp duration increases. Onset ramp associated AEP is not apparent beyond the 150‐msec condition. Stepwise correlational analyses are being performed to clarify the apparent dichotomous onset/offset results.

ISSN:0001-4966    

DOI:10.1121/1.1982607

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP

摘要:

Ultrasonic attenuation was measured in dimethyl sulfoxide mixtures over the frequency and temperature range 5–200 MHz and 25°C to − 80°C. At the higher temperatures the quantity α/f2was found to be independent of frequency and in excess of the value calculated from the classical Stokes equation for shear viscosity. The excess attenuation can be attributed to a volume viscosity, which is two‐thirds of the shear viscosity. At the lower temperatures α/f2was found to be highly frequency dependent and less than that predicted by the Stokes equation. Furthermore, the data indicate that both shear and volume viscosities are relaxing with a single relaxation time. The low value of the excess attenuation observed at high tempeatures suggests that there are no specific hydrogen bonded complexes being formed. The dramatic decrease in α/f2with increasing frequency at low temperatures seems to indicate the onset of a glassy state.

ISSN:0001-4966    

DOI:10.1121/1.1982609

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP

摘要:

For rating the noise of broad‐band sources the custom is to utilizeA‐weighted levels, but there is no consensus on the subjective importance of pure‐tone components that may be present. This study was to provide some direct evidence on this point. Nine subjects participated, individually, and the procedure was to have the subject match pairs of noises by adjusting the level of one of them. Two experiments used a modified random noise to which a pure tone in the range 250–2000 Hz could be added. The first experiment involved a simple comparison in a quiet environment. The second involved similar noises but with the addition of a local “wanted” sound in the form of music, and the subject matched noises from the viewpoint of “intrusiveness.” A third experiment was similar to the first but utilized actual machine noises as the basic spectra. All three experiments indicated that theA‐weighted level remains an adequate (slightly conservative) rating number even when pure tones are present.

ISSN:0001-4966    

DOI:10.1121/1.1982621

出版商:Acoustical Society of America    

年代:1973

数据来源: AIP