Volume 108, Issue 4, October 2000
- acoustical news—usa
- acoustical news—international
- technical program summary
- book reviews
- reviews of acoustical patents
- vocalization in animals and humans: papers from a 1999 symposium in berlin
- general linear acoustics 
- nonlinear acoustics 
- aeroacoustics, atmospheric sound 
- underwater sound 
- ultrasonics, quantum acoustics, and physical effects of sound 
- transduction 
- structural acoustics and vibration 
- noise: its effects and control 
- architectural acoustics 
- acoustic signal processing 
- physiological acoustics 
- psychological acoustics 
- speech production 
- speech perception 
- speech processing and communication systems 
- bioacoustics 
- letters to the editor
Index of content:
- BOOK REVIEWS
108(2000); http://dx.doi.org/10.1121/1.1289662View Description Hide Description
108(2000); http://dx.doi.org/10.1121/1.1289701View Description Hide Description
- REVIEWS OF ACOUSTICAL PATENTS
108(2000); http://dx.doi.org/10.1121/1.1310665View Description Hide Description
The purpose of these acoustical patent reviews is to provide enough information for a Journal reader to decide whether to seek more information from the patent itself. Any opinions expressed here are those of the reviewers as individuals and are not legal opinions. Printed copies of United States Patents may be ordered at $3.00 each from the Commissioner of Patents and Trademarks, Washington, DC 20231. Patents are available via the Internet at http://www.uspto.gov.
- VOCALIZATION IN ANIMALS AND HUMANS: PAPERS FROM A 1999 SYMPOSIUM IN BERLIN
108(2000); http://dx.doi.org/10.1121/1.1289204View Description Hide Description
To find out whether there exist additional regions in the pontine brainstem, apart from the phonatory motoneuron pools involved in vocal motor control, the effects of a localized blockade of excitatory neurotransmission in the pons were studied on squirrel monkey vocalization. Vocalization was elicited by electrical stimulation of the periaqueductal gray of the midbrain. Blockade was carried out by stereotaxic injections of kynurenic acid, a nonspecific glutamate antagonist. It was found that injections made into the ventrolateral pons around the ventral nucleus of the lateral lemniscus and superior olive could block periaqueductally elicited vocalization. Injections were only effective ipsilaterally, not contralaterally to the stimulation site. The blockade was limited to one particular class of calls, all of which had in common a characteristic stereotyped frequency modulation over several kHz. It is concluded that critical processing steps of vocal motor control take place in the periolivary region.
Resonance properties of the vocal folds: In vivo laryngoscopic investigation of the externally excited laryngeal vibrations108(2000); http://dx.doi.org/10.1121/1.1289205View Description Hide Description
The study presents the first attempt to investigate resonance properties of the living vocal folds by means of laryngoscopy. Laryngeal vibrations were excited via a shaker placed on the neck of a male subject and observed by means of videostroboscopy and videokymography (VKG). When the vocal folds were tuned to the phonation frequency of 110 Hz and sinusoidal vibration with sweeping frequency (in the range 50–400 Hz) was delivered to the larynx, three clearly pronounced resonance peaks at frequencies around 110, 170, and 240 Hz were identified in the vocal fold tissues. Different modes of vibration of the vocal folds, observed as distinct lateral-medial oscillations with one, two, and three half-wavelengths along the glottal length, respectively, were associated with these resonance frequencies. At the external excitation frequencies below 100 Hz, vibrations of the ventricular folds, aryepiglottic folds and arytenoid cartilages were dominant in the larynx.
108(2000); http://dx.doi.org/10.1121/1.1289206View Description Hide Description
The harmonics-to-noise ratio (HNR) has been used to quantify the waveform irregularity of voice signals [Yumoto et al., J. Acoust. Soc. Am. 71, 1544–1550 (1982)]. This measure assumes that the signal consists of two components: a harmonic component, which is the common pattern that repeats from cycle-to-cycle, and an additive noise component, which produces the cycle-to-cycle irregularity. It has been shown [J. Qi, J. Acoust. Soc. Am. 92, 2569–2576 (1992)] that a valid computation of the HNR requires a nonlinear time normalization of the cycle wavelets to remove phase differences between them. This paper shows the application of functional data analysis to perform an optimal nonlinear normalization and compute the HNR of voice signals. Results obtained for the same signals using zero-padding, linear normalization, and dynamic programming algorithms are presented for comparison. Functional data analysis offers certain advantages over other approaches: it preserves meaningful features of signal shape, produces differentiable results, and allows flexibility in selecting the optimization criteria for the wavelet alignment. An extension of the technique for the time normalization of simultaneous voice signals (such as acoustic, EGG, and airflow signals) is also shown. The general purpose of this article is to illustrate the potential of functional data analysis as a powerful analytical tool for studying aspects of the voice production process.
108(2000); http://dx.doi.org/10.1121/1.1289207View Description Hide Description
A decomposition algorithm that uses a pitch-scaled harmonic filter was evaluated using synthetic signals and applied to mixed-source speech, spoken by three subjects, to separate the voiced and unvoiced parts. Pulsing of the noise component was observed in voiced frication, which was analyzed by complex demodulation of the signal envelope. The timing of the pulsation, represented by the phase of the anharmonic modulation coefficient, showed a step change during a vowel-fricative transition corresponding to the change in location of the noise source within the vocal tract.Analysis of fricatives /β, v, ð, z, ȝ, v̥, ʕ/ demonstrated a relationship between steady-state phase and place, and glides confirmed that the main cause was a place-dependent delay.
108(2000); http://dx.doi.org/10.1121/1.1289208View Description Hide Description
It was reported to the first author that a female dog–wolf mix showed anomalously rough-sounding vocalization. Spectral analysis of recordings of the vocalization revealed frequency occurrences of subharmonics, biphonation (two independent pitches) and chaos. Since these nonlinear phenomena are currently widely discussed as integral to mammalian vocalization [Wilden et al., Bioacoustics9, 171–196 (1988)] or as indicators of vocal pathologies [Herzel et al., J. SpeechHearing Res. 37, 1008–1019 (1994); Riede et al., Z. Sgtkde 62 Suppl: 198–203 (1997)], we sought to understand the production mechanism of the observed vocal instabilities. First the frequency of nonlinear phenomena in the calls was determined for the female and four additional individuals. It turned out that these phenomena appear, but much less frequently in the repertoire of the four other animals. The larynges of the female and two other individuals were dissected post mortem. There was no apparent asymmetry of the vocal folds but a slight asymmetry of the arytenoid cartilages. The most pronounced difference, however, was an upward extension of both vocal folds of the female. This feature is reminiscent of “vocal lips” (syn. “vocal membranes”) in some primates and bats. Spectral analysis of the female’s voice showed clear similarities with an intensively studied voice of a human who produces biphonation intentionally. Finally, the possible communicative relevance of nonlinear phenomena is discussed.
108(2000); http://dx.doi.org/10.1121/1.1289209View Description Hide Description
Respiratory abdominal movements associated with vocalization were recorded in awake squirrel monkeys. Several call types, such as peeping, trilling, cackling, and err-chucks, were accompanied by large vocalization-correlated respiratory movements (VCRM) that started before vocalization. During purring, in contrast, only small VCRM were recorded that started later after vocal onset. VCRM during trill calls, a vocalization type with repetitive frequency modulation, showed a modulation in the rhythm of the frequency changes. A correlation with amplitude modulation was also present, but more variable. As high frequencies need a higher lungpressure for production than low frequencies, the modulation of VCRM seems to serve to optimize the lungpressure in relation to the vocalization frequency. The modulation, furthermore, may act as a mechanism to produce different trill variants. During err-chucks and staccato peeps, which show a large amplitude modulation, a nonmodulated VCRM occurred. This indicates the existence of a laryngeal amplitude-controlling mechanism that is independent from respiration.
- GENERAL LINEAR ACOUSTICS 
108(2000); http://dx.doi.org/10.1121/1.1289922View Description Hide Description
In this paper boundary element methods(BEM) are mated with near-field acoustical holography (NAH) in order to determine the normal velocity over a large area of a fuselage of a turboprop airplane from a measurement of the pressure (hologram) on a concentric surface in the interior of the aircraft. This work represents the first time NAH has been applied in situ, in-flight. The normal fuselage velocity was successfully reconstructed at the blade passage frequency (BPF) of the propeller and its first two harmonics. This reconstructed velocity reveals structure-borne and airborne sound-transmission paths from the engine to the interior space.
108(2000); http://dx.doi.org/10.1121/1.1289921View Description Hide Description
Many acoustic problems (especially in environmental acoustics) involve half-space domains bounded by a plane subjected to normal admittance boundary conditions. In the “low” frequency domain, the numerical treatment of such problems usually relies on boundary element methods based on a particular Green’s function suited for the half-(admittance) plane. In the present paper, an alternative hybrid finite/infinite element scheme is proposed. The method relies on a direct treatment of nonhomogeneous boundary conditions along infinite element edges (or faces). The procedure is validated through comparisons with an available reference solution.
108(2000); http://dx.doi.org/10.1121/1.1310193View Description Hide Description
Plane wave incidence on a rigid biconic target is considered. A biconic reflector consists of two cones truncated by planes perpendicular to their axes and joined at their smaller flat faces. The cone angles are allowed to be variable, provided their sum is equal to 90°. The backscattering cross section is expressed in terms of a surface integral of the geometrical acoustics field, which results from incident singly and doubly reflected rays. A saddle-point calculation gives a first-order high-frequency approximation in which the backscattering cross section is proportional to the incident wave number and a function of the angle of incidence, cone angles, and inner and outer radii of the truncated cones. This expression is algebraically complex but easy to implement numerically. Results are presented that exercise the parameters of the problem. An interesting result of the solution is that for fixed outer radii there is a nonzero optimum inner radius for backscattering strength. For broadside incidence on 45° cones with equal outer radii, this optimum value is approximately equal to 11% of the outer radius.
108(2000); http://dx.doi.org/10.1121/1.1289920View Description Hide Description
The statistics of the ultrasonic resonance peaks of a finite elastic body are investigated. The distribution of peak phases, and the normalized variance of peak amplitudes, are shown to be consistent with a hypothesis that the modes themselves are complex Gaussian random numbers. A value for the ratio of the standard deviations of the imaginary and real parts of the modes is found to fit the data, and to bring recent theory of power variances into better accord with measurements.
108(2000); http://dx.doi.org/10.1121/1.1289365View Description Hide Description
In this paper are described experimental observations which are concerned by the propagation of pulsed ultrasonicwaves transmitted through a limited one dimensional periodic granular medium submitted to a static force. This study—which is limited to a time domain analysis—exhibits experimental results which depend on the polarization of the acoustic excitation. In the case of compressional excitation, spherical Rayleigh type surface waves propagate around the beads. In the case of shear excitation, the experimental recordings point out the existence of a very low signal, the frequency of which is equal to the cut-off frequency of the chain. Moreover it is established that the frequency value varies with the radius of the bead, the normal force applied to the beads, and the mechanical properties of the material.
- NONLINEAR ACOUSTICS 
108(2000); http://dx.doi.org/10.1121/1.1289666View Description Hide Description
An exact treatment of the propagation of axisymmetric waves in coaxial anisotropic assembly of piezoelectric rod systems is presented. The rod system consists of an arbitrary number of coaxial layers, each possessing transversely isotropic symmetry properties. The treatment, which is based on the transfer matrix technique, is capable of deriving the dispersion relations for a variety of situations. These include the case of a single rod system that is either embedded in an infinitely extended solid or fluid host or kept free. The procedure is also adapted to derive approximate solutions for the cases of a periodic fiber distribution in a matrix material, which model unidirectional fiber-reinforced composites. The results are numerically illustrated for a widely used piezoelectric-polymer composite. It is seen that piezoelectric coupling can significantly change the morphology of the dispersive behavior of the composite.
108(2000); http://dx.doi.org/10.1121/1.1289665View Description Hide Description
This article presents a model for second-harmonic generation in a sound beam that is reflected from or transmitted through a curved interface. Propagation in homogeneous fluids is assumed. Simple analytic solutions are derived for the case of focused Gaussian beams. The solutions are used to illustrate the effects of focusing or defocusing due to curvature of the interface, in combination with impedance change at the interface, on energy transfer from the fundamental to the second harmonic.
108(2000); http://dx.doi.org/10.1121/1.1289367View Description Hide Description
The problem of steady streaming around a rigid isolated sphere in a plane standing acoustic field is considered. Existing results in the literature have been generalized to allow for noncompactness of the sphere, and the influence of fluid compressibility on the streaming behavior has been included. It is found that in the high-frequency limit of interest for which the streaming is strongest, the effective steady slip velocity at the edge of the inner boundary layer region that is responsible for driving the steady streaming in the bulk of the fluid in the outer region, has a complex variation over the surface of the sphere that depends on (i) the sphere position (with respect to the node/antinode of the acoustic field), (ii) the extent of sphere compactness, and (iii) on a well-defined function (representing compressibility effects) of the fluid Prandtl number and its ratio of specific heats. Not surprisingly, the contribution from this function is negligible when the host fluid is a liquid. The steady streaming behavior around the sphere is demonstrated with the help of flow streamlines for various cases in the diffusive limit of weak outer flow for low streaming Reynolds numbers.