Wide Range Of Fundamental Frequencies Research Articles

High and Wide: An In Silico Investigation of Frequency, Intensity, and Vibrato Effects on Widely Applied Acoustic Voice Perturbation and Noise Measures

This in silico study explored the effects of a wide range of fundamental frequency (fo), source-spectrum tilt (SST), and vibrato extent (VE) on commonly used frequency and amplitude perturbation and noise measures. Using 53 synthesizedtones produced in Madde, the effects of stepwise increases in fo, intensity (modeled by decreasing SST), and VE on the PRAAT parameters jitter % (local), relative average perturbation (RAP) %, shimmer % (local), amplitude perturbation quotient 3 (APQ3) %, and harmonics-to-noise ratio (HNR) dB were investigated. A secondary experiment was conducted to determine whether any fo effects on jitter, RAP, shimmer, APQ3, and HNR were stable. A total of 10 sinewaves were synthesizedin Sopran from 100 to 1000Hz using formant frequencies for /a/, /i/, and /u/-like vowels, respectively. All effects were statistically assessed with Kendall's tau-b and partial correlation. Increasing fo resulted in an overall increase in jitter, RAP, shimmer, and APQ3 values, respectively (P<0.01). Oscillations of the data across the explored fo range were observed in all measurement outputs. In the Sopran tests, the oscillatory pattern seen in the Madde fo condition remained and showed differences between vowel conditions. Increasing intensity (decreasing SST) led to reduced pitch and amplitude perturbation and HNR (P<0.05). Increasing VE led to lower HNR and an almost linear increase of all other measures (P<0.05). These novel data offer a controlled demonstration for the behavior of jitter (local) %, RAP %, shimmer (local) %, APQ3 %, and HNR (dB) when varying fo, SST, and VE in synthesizedtones. Since humans will vary in all of these aspects in spoken language and vowel phonation, researchers should take potential resonance-harmonics type effects into account when comparing intersubject or preintervention and postintervention data using these measures.

Space Vector-Based Hybrid Pulse Width Modulation for Voltage Source Inverters Using Novel Euclidean Distance Mapping Technique

In this article, a novel Euclidean distance mapping (EDM) technique for space vector pulse width modulated (SVPWM) voltage source inverter (VSI) is presented. The EDM technique processes space vector diagram (SVD) as an image, which simplifies execution of SVPWM. In the proposed technique, Euclidean distance calculation between all eight switching vectors and the tip of the revolving reference voltage vector for every subcycle is carried out. The identification of nearest three voltage vectors (NTV) and switching sequence designs are done on the basis of these Euclidean distances. The EDM-SVPWM technique achieves improvement in the inverter performance in the context of the factors like stator flux ripple over a subcycle, distortion factor (DF), total harmonics distortion (THD) of line voltage, and line current ripple of the inverter. The performance of EDM-SVPWM technique is verified analytically and confirmed experimentally by hardware implementation over the wide range of fundamental frequencies and modulation indices.

Are men better than women at acoustic size judgements?

Formants are important phonetic elements of human speech that are also used by humans and non-human mammals to assess the body size of potential mates and rivals. As a consequence, it has been suggested that formant perception, which is crucial for speech perception, may have evolved through sexual selection. Somewhat surprisingly, though, no previous studies have examined whether sexes differ in their ability to use formants for size evaluation. Here, we investigated whether men and women differ in their ability to use the formant frequency spacing of synthetic vocal stimuli to make auditory size judgements over a wide range of fundamental frequencies (the main determinant of vocal pitch). Our results reveal that men are significantly better than women at comparing the apparent size of stimuli, and that lower pitch improves the ability of both men and women to perform these acoustic size judgements. These findings constitute the first demonstration of a sex difference in formant perception, and lend support to the idea that acoustic size normalization, a crucial prerequisite for speech perception, may have been sexually selected through male competition. We also provide the first evidence that vocalizations with relatively low pitch improve the perception of size-related formant information.

The effect of the driving frequencies on the electrical asymmetry of dual-frequency capacitively coupled plasmas

In capacitively coupled radio frequency discharges driven by two consecutive phase-locked harmonics, the electrical asymmetry effect (EAE) allows one to generate a dc self-bias as a function of the phase shift, θ, between the driving harmonics. If the two frequencies are chosen to be 13.56 and 27.12 MHz, the mean ion energy at both electrodes can be varied by a factor of about 2 by tuning θ at nearly constant ion flux. Until now the EAE has only been investigated in discharges operated at a fundamental frequency of f = 13.56 MHz. Here, we study the effect of changing this fundamental frequency on the performance of the EAE, i.e. on the electrical generation of a dc self-bias, the control range of the mean ion energy, and on the ion flux at both electrodes as a function of θ, by kinetic particle-in-cell/Monte Carlo simulations and theoretical modelling. We use argon gas and cover a wide range of fundamental frequencies (0.5 MHz ⩽ f ⩽ 60 MHz) and secondary electron yields. We find that the performance of the EAE is significantly worse at lower frequencies, i.e. the control range of the dc self-bias and, thus, the control range of the mean ion energy are strongly reduced. Based on the analytical model (i) the enhanced charged dynamics at lower frequencies and (ii) the transition of the electron heating mode induced by changing f are found to be the reasons for this effect.

A cervid vocal fold model suggests greater glottal efficiency in calling at high frequencies.

Male Rocky Mountain elk (Cervus elaphus nelsoni) produce loud and high fundamental frequency bugles during the mating season, in contrast to the male European Red Deer (Cervus elaphus scoticus) who produces loud and low fundamental frequency roaring calls. A critical step in understanding vocal communication is to relate sound complexity to anatomy and physiology in a causal manner. Experimentation at the sound source, often difficult in vivo in mammals, is simulated here by a finite element model of the larynx and a wave propagation model of the vocal tract, both based on the morphology and biomechanics of the elk. The model can produce a wide range of fundamental frequencies. Low fundamental frequencies require low vocal fold strain, but large lung pressure and large glottal flow if sound intensity level is to exceed 70 dB at 10 m distance. A high-frequency bugle requires both large muscular effort (to strain the vocal ligament) and high lung pressure (to overcome phonation threshold pressure), but at least 10 dB more intensity level can be achieved. Glottal efficiency, the ration of radiated sound power to aerodynamic power at the glottis, is higher in elk, suggesting an advantage of high-pitched signaling. This advantage is based on two aspects; first, the lower airflow required for aerodynamic power and, second, an acoustic radiation advantage at higher frequencies. Both signal types are used by the respective males during the mating season and probably serve as honest signals. The two signal types relate differently to physical qualities of the sender. The low-frequency sound (Red Deer call) relates to overall body size via a strong relationship between acoustic parameters and the size of vocal organs and body size. The high-frequency bugle may signal muscular strength and endurance, via a ‘vocalizing at the edge’ mechanism, for which efficiency is critical.

A General Model for Estimating the Laminated Steel Losses Under PWM Voltage Supply

The new model is based on a modified Steinmetz equation and employs a hysteresis-loss multiplicative coefficient and a combined coefficient for eddy-current and excess losses, both coefficients being variable with induction and frequency. The material model coefficients are first identified through multifrequency tests with sine-wave excitation. The iron-loss increase due to pulsewidth-modulation supply is estimated using global waveform parameters of the nonsinusoidal voltage. The study includes three different grades of non-grain-oriented electric steel. The data cover a wide range of fundamental frequency from 10 to 600 Hz and induction from 0.05 to 2 T. The errors of the computational model are small at relatively low fundamental frequency and increase thereafter. The main advantages of the model are its simplicity of use and minimal data requirements.

Tunable dispersion filter design for piano synthesis

The tunable dispersion filter is a new design approach presented in this letter to provide dispersion modeling for digital waveguide synthesis of musical instruments, which do not produce extremely inharmonic sounds, such as the piano. We propose to use a cascade of second-order allpass filters for modeling dispersion. The filter coefficients can be calculated by using simple formulae based on the Thiran allpass filter design, which is usually used for fractional delay approximation. Unlike the previous allpass filter approximations, this filter design is easily scalable to produce various inharmonicity values for a wide range of fundamental frequencies.

A method for pitch extraction of speech signals using autocorrelation functions through multiple window lengths

A high-performance method for pitch extraction is proposed for the purposes of real-time sequential speech processing that can be used in such applications as speech rate conversion systems. According to this method, autocorrelation functions of the input speech waveforms are calculated for one analyzed point in time using multiple lengths of the analysis windows, and the largest peaks of each autocorrelation function are detected within the appropriate ranges, after which the optimum pitch period is selected by weighting the candidates of the pitch period obtained by the number of windows. Such selection processing is carried out independently for each analyzed point without using such characteristics as the continuity of the fundamental frequencies of the entire speech segment. This method was applied to analysis of a large number of speech materials, including recordings made by different speakers and speech samples mixed with noise. The tests have demonstrated that the proposed method features pitch extraction potentials superior to those of the cepstrum pitch determination method and the LPC residual autocorrelation method within a wide range of fundamental frequencies and power levels. © 1999 Scripta Technica, Electron Comm Jpn Pt 3, 83(2): 67–79, 2000

Verbal indicators of depression.

Speech content, voice quality, and temporal pacing of speech were evaluated for 11 well and 11 depressed women. Sadness was the dominant mood of the depressed women's speech, whereas happiness and mood neutrality characterized the well women's speech. The well women's tone of voice changed with the content of their speech. The well women spoke with a wide range of fundamental frequency, and the average fundamental frequency of their voices changed according to speech content. In contrast, the depressed women spoke with a narrow range of fundamental frequency, and the average fundamental frequency of their speech was unaffected by speech content. The depressed women spoke with longer pauses than the well women did. The results of this study contribute to the understanding of measures for assessing depression.

Theory of vocal registers: Review of the literature

For artistic voice production in Western music culture the singer is expected to develop and maintain a pleasing quality over a wide range of fundamental frequencies and intensities. To cope with the demands the singer employs different mechanisms called registers, which, especially prior to training, may exhibit marked differences in timbre. Whether a trained vocal artist chooses to use the characteristic timbre of a particular register or to try to make it blend with the timbre of an adjoining register depends on several factors including (1) the mood or character of the literary text and the music, (2) the performance practice of a particular style, and (3) the tenets and techniques of a specific vocal method. This review examines the literature of vocal registers with regard to number, names, ranges, sources, pedagogy, equalization, safety, and aesthetics. Four primary lines of investigation into the nature of vocal registers were revealed: (1) laryngeal adjustment, (2) supra-glottal coupling to the larynx, (3) subglottal coupling to the larynx, and (4) formant enhancement of different partials. García's laryngeal adjustment definition of vocal registers is modified to include nonlaryngeal determinants.