Harmonic-intensity analysis of normal and hoarse voices

Objective evaluation of normal and hoarse voices is performed considering the characteristic that hoarse voices show a prominent fundamental frequency intensity compared with harmonics in the voice spectrum. The relative harmonic intensity Hr, obtained from a stable portion of the sustained vowel/a/, is defined as the intensity of the second and higher harmonics expressed as a percentage of the total voice intensity. Ninety-five percent of the normal voices examined have Hr larger than the critical value of 67.2%, whereas 90% of the hoarse voices have Hr smaller than the critical value. The harmonic-intensity analysis thus provides good discrimination between normal and hoarse voices.     

A comparison of intergestural patterns in deaf and hearing adult speakers: implications from an acoustic analysis of disyllables.

Coarticulation studies in speech of deaf individuals have so far focused on intrasyllabic patterning of various consonant-vowel sequences. In this study, both inter- and intrasyllabic patterning were examined in disyllables /symbol see text #CVC/ and the effects of phonetic context, speaking rate, and segment type were explored. Systematic observation of F2 and durational measurements in disyllables minimally contrasting in vocalic ([i], [u,][a]) and in consonant ([b], [d]) context, respectively, was made at selected locations in the disyllable, in order to relate inferences about articulatory adjustments with their temporal coordinates. Results indicated that intervocalic coarticulation across hearing and deaf speakers varied as a function of the phonetic composition of disyllables (b_b or d_d). The deaf speakers showed reduced intervocalic coarticulation for bilabial but not for alveolar disyllables compared to the hearing speakers. Furthermore, they showed less marked consonant influences on the schwa and stressed vowel of disyllables compared to the hearing controls. Rate effects were minimal and did not alter the coarticulatory patterns observed across hearing status. The above findings modify the conclusions drawn from previous studies and suggest that the speech of deaf and hearing speakers is guided by different gestural organization.     

Effects of laryngeal endoscopy on the vocal performanceof young adult females with normal voices

This study investigated changes in maximum phonation time andacoustic and perceptual measures of voice following topical anesthesia and laryngeal endoscopy with the flexible endoscope. Forty-four females, aged 18–33 years and with normal voices, performed four vocal tasks: (a) 3-second /i/ prolongation, (b) maximum phonation time on /i/, (c) stepwise scale-singing, and (d) reading a standard passage. Subjects performed these tasks prior to anesthesia, after anesthesia, and again during laryngeal endoscopy. Voice samples were analyzed for jitter, shimmer, harmonic-to-noise ratio, speaking fundamental frequency, maximum phonational frequency range, maximum phonation time, harshness, and breathiness. Results demonstrated significant reductions in maximum phonational frequency range following anesthesia and, during laryngeal endoscopy, reductions in maximum phonation time and increases in speaking fundamental frequency, minimum fundamental frequency on scale-singing, and breathiness. Clinicians using laryngeal endoscopy for evaluation and management of vocal dysfunction should, therefore, consider the possible effects of these procedures on vocal functioning.     

An experimental study of the fluctuations of acoustic signals reflected from ships

Results of an experimental study of amplitude fluctuations in echo signals received from ships and their wakes are presented for the cases of vertical and horizontal sounding in a wide range of high sonic and ultrasonic frequencies. Dependences of the amplitude variation coefficients of echo signals on the speed of ship motion, the sounding frequency, the duration of sounding pulses, and the height of wind waves on the sea surface are analyzed. The probability characteristics of echo signals reflected from ship hulls and from wakes at different depths are discussed.     

An analysis of transverse fluctuations in multidimensional tunneling

We examine the asymptotic behaviour of the ground state tunnel-splitting of the multidimensional double well, with non-quadratic minima, where instanton techniques are inapplicable. We apply the recently developed path decomposition expansion for two model problems; the important effects of the transverse degrees of freedom are explored. In particular we discuss tunneling in the presences of a vacuum valley, which describes features exhibited in SU(2) gauge theories in a finite volume.     

The acoustic analysis of tone differentiation as a means for assessing tone production in speakers of Cantonese

This paper reports on a methodology for acoustically analyzing tone production in Cantonese. F0 offset versus F0 onset are plotted for a series of tokens for each of the six tones in the language. These are grouped according to tone type into a set of six ellipses. Qualitative visual observations regarding the degree of differentiation of the ellipses within the tonal space are summarized numerically using two indices, referred to here as Index 1 and Index 2. Index 1 is a ratio of the area of the speaker's tonal space and the average of the areas of the ellipses of the three target tones making up the tonal space. Index 2 is a ratio of the average distance between all six tonal ellipses and the average of the sum of the two axes for all six tone ellipses. Using this methodology, tonal differentiation is compared for three groups of speakers; normally hearing adults; normally hearing children aged from 4-6 years; and, prelinguistically deafened cochlear implant users aged from 4-11 years. A potential conundrum regarding how tone production abilities can outstrip tone perception abilities is explained using the data from the acoustic analyses. It is suggested that young children of the age range tested are still learning to normalize for pitch level differences in tone production. Acoustic analysis of the data thus supports results from tone perception studies and suggests that the methodology is suitable for use in studies investigating tone production in both clinical and research contexts.     

Temporal characteristics of nasalization in children and adult speakers of American English and Korean during production of three vowel contexts

The purpose of this study was to identify and compare the temporal characteristics of nasalization in relation to (1) languages, (2) vowel contexts, and (3) age groups. Two distinct acoustic energies from the mouth and nose were recorded during speech production (/pamap, pimip, pumup/) using two microphones to obtain the absolute and proportional measurements on the acoustic temporal characteristics of nasalization. Twenty-eight normal adults (14 American English and 14 Korean speakers) and 28 normal children (14 American English and 14 Korean speakers) participated in this study. In both languages, adults showed shorter duration of nasalization than children within all three vowel contexts. The high vowel context revealed longer duration of nasalization than the low vowel context in both languages. There was no significant difference of temporal characteristics of nasalization between American English and Korean. Nasalization showed different timing characteristics between children and adults across vowel contexts. The results are discussed in association with developmental coarticulation and the relationship between acoustic consequences of articulatory events and vowel height.     

Habitual use of vocal fry in young adult female speakers

The purpose of this study was to examine the use of vocal fry in young adult Standard American-English (SAE) speakers. This was a preliminary attempt (1) to determine the prevalence of the use of this register in young adult college-aged American speakers and (2) to describe the acoustic characteristics of vocal fry in these speakers. Subjects were 34 female college students. They were native SAE speakers aged 18-25 years. Data collection procedures included high quality recordings of two speaking conditions, (1) sustained isolated vowel /a/ and (2) sentence reading task. Data analyses included both perceptual and acoustic evaluations. Results showed that approximately two-thirds of this population used vocal fry and that it was most likely to occur at the end of sentences. In addition, statistically significant differences between vocal fry and normal register were found for mean F(0) minimum, F(0) maximum, F(0) range, and jitter local. Preliminary findings were taken to suggest that use of the vocal fry register may be common in some adult SAE speakers.     

Suppression of acoustic noise in the measurements of wall pressure fluctuations

It is shown that, in hydrodynamic noise measurements in the presence of acoustic noise acting upon the pressure fluctuation receiver, spatial filtering methods should provide the best results. Active methods are developed for suppressing the acoustic noise that affects a miniature receiver in the course of turbulent pressure fluctuation measurements. The methods are based on complicating the structure of the measuring transducer by introducing an extra compensating sensing element whose characteristics are identical with those of the main sensing element. The spatial filtering of small-scale turbulent pressure fluctuations by a finite-size electroacoustic transducer is used as the basis for the development of noise-compensated measuring systems, as well as methods of measuring the turbulent pressure fluctuations by receivers with noise compensation. A numerical study of the wave-number filtering of acoustic noise in wall pressure measurements by a noise-compensated receiver is performed.     

An analysis of acoustic oscillations in dust plasma structures

Low-frequency oscillations in the density of dust particles, which are spontaneously excited in the standing plasma column of a dc glow discharge in neon, were experimentally studied. The longitudinal waves were monitored by a special visualization technique, and the dust sound oscillation characteristics were determined and analyzed using specially developed algorithm and data processing software. It was established that the longitudinal waves propagate from anode to cathode, the frequency and wavevector of the dust sound oscillations being dependent on the discharge current, gas pressure, particle density in the dust cloud, and spatial coordinates. Two-dimensional (2D) fields of the main wave characteristics were studied using an original algorithm. The possible mechanisms of excitation of the dust sound oscillations is discussed. The experimental spatial distributions of the wave parameters are compared to the patterns obtained within the framework of various theoretical models.     

汉语促化元音的声学分析

汉语入声音节中的元音多表现为短而促的特点,为分析这一现象,借鉴参数统计模型的思路,提出了声学参数的选取、参数作用的检验与参数分类的自动检测的一套方法。采用了概率分布的一般方法对声学参数进行描写以选取有效声学参数,采用了二元与多元逻辑回归模型的方法对参数的分类作用进行检验,采用了支持向量机模型对参数的分类结果进行自动检测。模型检验显示,对促化元音的外部分类,时长与DCT_1~3四维参数有显著性作用,对内部分类,DCT_0~3四维参数有显著性作用。自动检测结果显示,外部分类中四维参数的促化元音检测率约仅为43.6%,内部检测的总检测率约为96.1%,说明促化作为元音的附加性特征更为突出。     

An acoustic analysis of vowels in checked syllables in Chinese

Vowels in checked syllables are almost short and abrupt in Chinese Mandarin dialects. This paper proposed a parametric statistical modeling for the analysis of these vowels.The parameters were described empirically with the method of probability distribution. The effects of the multiparameter classifications were estimated by the binary and multinomial logistic models, and the method of support vector machine was adopted to carry out the pattern recognition of the classifications. The results show that the parameters of duration, DCT_(1-3)are significant to the external classification, and the parameters of DCT_(0-3) have significant main effects on the internal classification. The automatic testing shows that the hit rate of the external pattern recognition is only 43.6% but the rate is 96.1% of the internal. It indicates that the abrupt feature should be additive rather than distinctive.     

Vocal stability in functional dysphonic versus healthy voices at different times of voice loading

Functional (nonorganic) dysphonia is often characterized by vocal instability. The purpose of the prospective study was to examine whether there is a difference in vocal instability of functional dysphonic voices compared with healthy ones, this means whether electroglottographic perturbation values differ (1) between healthy and dysphonic voices and (2) between two subgroups of the dysphponic voices (hpertonic and hypotonic dysphonic voices). Twenty-three patients with hypertonic functional dysphonia, 9 with hypotonic functional dysphonia and 31 healthy nonsmokers, were each examined electroglottographically before (Ex 1), immediately after (Ex 2), and 1 hour after (Ex 3) voice loading. Perturbations of frequency, amplitude, quasi-open-quotient, and contact-index were calculated from the EGG signal. At all three times of examination, hypertonic dysphonic voices showed higher perturbations than healthy voices, and they had higher perturbations than hypotonic dysphonic voices before and 1 hour after voice loading. Hypotonic dysphonic voices showed higher perturbations than healthy voices only 1 hour after voice loading. Voice loading induced different reactions in dysphonic voices: Some voices showed increased perturbations, and others exhibited normal or even decreased perturbation immediately after voice loading. Examination of electroglottographic-derived perturbations immediately after voice loading seems not to be useful. Differentiation of hypertonic and hypotonic dysphonic voices was possible with an estimated sensitivity of 88.9% and a specificity of 87.0% by using the sum of the amplitude-perturbation and the quasi-open-quotient-perturbation measured before voice loading.     

An experimental study of the characteristics of the acoustic field of zero normal plate modes

The sources of systematic errors in measuring the amplitude and propagation velocity of normal waves are analyzed. Criteria are proposed for estimating the distances beyond which a wave can be considered a normal wave. The measurement method and corresponding experimental setup are described. Experimental estimates are obtained for the distances necessary for the formation of symmetric zero modes of horizontally polarized normal waves and Lamb waves in thin strips at frequencies of 1.8 and 2.5 MHz.     

Annoyance due to railway vibration at different times of the day

The time of day when vibration occurs is considered as a factor influencing the human response to vibration. The aim of the present paper is to identify the times of day during which railway vibration causes the greatest annoyance, to measure the differences between annoyance responses for different time periods and to obtain estimates of the time of day penalties. This was achieved using data from case studies comprised of face-to-face interviews and internal vibration measurements (N=755). Results indicate that vibration annoyance differs with time of day and that separate time of day weights can be applied when considering exposure-response relationships from railway vibration in residential environments.     

Properties of geodesic acoustic modes and the relation to density fluctuations

The geodesic acoustic mode (GAM) is a high frequency branch of zonal flows, which is observed in toroidal plasmas. Because of toroidal curvature effects, density fluctuations are excited, which are investigated with the O-mode correlation reflectometer at TEXTOR. This Letter reports on the poloidal distribution of GAM induced density fluctuation and compares them with theoretical predictions. The influence of the GAM flows on the ambient turbulence is studied, too.     

Pseudogap and spin fluctuations in the normal state of the electron-doped cuprates

We present reliable many-body calculations for the t-t(')-t(')-U Hubbard model that explain in detail the results of recent angle-resolved photoemission experiments on electron-doped high-temperature superconductors. The origin of the pseudogap is traced to two-dimensional antiferromagnetic spin fluctuations whose calculated temperature-dependent correlation length also agrees with recent neutron scattering measurements. We make specific predictions for photoemission, for neutron scattering, and for the phase diagram.