Changes In Fundamental Frequency Research Articles

Effects of fundamental frequency changes on spoken sound loudness.

This study aimed to investigate the perception of loudness in response to changes in fundamental frequency (F0) in spoken sounds, as well as the influence of linguistic background on this perceptual process. The results revealed that participants perceived changes in F0 to have accompanying changes in loudness, with a trend of lower F0 sounds being perceived as louder than higher F0 sounds. This finding contrasts with previous studies on pure tones, where increases in frequency typically led to increases in loudness. Furthermore, the study examined differences between two distinct groups of participants: Chinese-speaking and English-speaking individuals. It was observed that English-speaking participants exhibited a greater sensitivity to minor intensity changes compared to Chinese-speaking participants. This discrepancy in sensitivity suggests that linguistic background may play a significant role in shaping the perception of loudness in spoken sound. The study's findings contribute to our understanding of how F0 variations are perceived in terms of loudness, and highlight the potential impact of language experience on this perceptual process.

A meta-analysis of expressive prosody in cochlear implant users

IntroductionProsody is used to express indexical (identifying the talker), linguistic (e.g., question intonation, lexical stress), pragmatic (e.g., contrastive stress, sarcasm), and emotional/affective functions. It is manifested through changes in fundamental frequency (f0), intensity, and duration. F0 and intensity are degraded when perceived through a cochlear implant (CI). The purpose of this meta-analysis is to compare expressive prosody in speech produced by CI users versus normal hearing peers. MethodsA systematic search of the literature found 25 articles that met all inclusion criteria. These articles were assessed for quality, and data pertaining to the expression of f0, intensity, and duration, as well as classification accuracy and appropriateness ratings from normal hearing listeners, were extracted and meta-analyzed using random effects models. ResultsThe articles included in the meta-analysis were generally of acceptable or high quality. Meta-analyses revealed significant differences between individuals with CIs vs. normal hearing on all measures except mean f0, mean intensity, and rhythm. Effect sizes were generally medium to large. There was significant heterogeneity across studies, but little evidence of publication bias. ConclusionsCI users speak with less variable f0, smaller f0 contours, more variable intensity, a slower speech rate, and reduced final lengthening at syntactic boundaries. These acoustic differences are reflected in significantly poorer ratings of speech produced by CI users compared to their normal hearing peers, as assessed by groups of normal hearing listeners. Because atypical expressive prosody is associated with negative outcomes, clinicians should consider targeting prosody when working with individuals who use CIs.

Acoustic Analyses of Tone Productions in Sequencing Contexts Among Cantonese-Speaking Preschool Children With and Without Childhood Apraxia of Speech.

Pitch variations (tone productions) have been reported as a measure to differentiate Cantonese-speaking children with and without childhood apraxia of speech (CAS). This study aims to examine fundamental frequency (F0) changes within syllables and the effects of syllable structure, lexical status, and syllable positions on F0 in Cantonese-speaking preschool children with and without CAS. Six children with CAS, six children with non-CAS speech sound disorder plus language disorder (S&LD), 22 children with speech sound disorder only (SSD), and 63 children with typical speech-language development (TD) performed the tone sequencing task (TST). Growth curve analysis was employed to analyze and compare the F0 values within syllables with three Cantonese tones (high level, high rising, and low falling). The analysis considered the effects of syllable structure (vowel and consonant-vowel), lexical status (word and nonword), and syllable position (initial, medial, and final) on F0, as well as comparisons within and between groups. Within each group, the effects of syllable structure and position on F0 values were found with different patterns. Between-group comparisons showed that the CAS group had reduced F0 contrasts. The CAS group could be differentiated from the control groups based on interactions of F0 with syllable structure and position, but not lexical status. The dissimilarity of F0 values detected between the CAS and SSD/TD groups was more prominent than that observed between the CAS and S&LD groups. This study demonstrated that Cantonese-speaking children with CAS had difficulty in varying F0 within syllables as compared to those without CAS, suggesting pitch variation difficulty and language-specific impairment profiles in CAS. Future investigations of objective measures for identifying Cantonese speakers with CAS and cross-linguistic investigations using growth curve analysis and the TST are suggested.

Primary resonance analysis of hyperelastic doubly curved shallow shells subjected to external loading

In this paper, primary resonance analysis of stiffened shallow shells with doubly curved ones is evaluated employing an analytical method. The shell material is hyperelastic, and the system is under external loading. The shell's mathematical model is developed using the first-order shear deformation theory (FSDT), considering von-Kármán's non-linear shell assumptions, multiple scales, and the Galerkin method. The Neo-Hookean hyperelastic type has been selected to explain the non-linear elasticity of the material. The stiffened shell geometric can be changed to different forms such as hyperbolic, cylindrical, and spherical shells by curvature components set. Several material parameters, number of stiffeners, geometrical ratio, etc., that affect shell oscillations results are examined and investigated in detail. According to the numerical results, it is characterized by increasing and decreasing the stiffener's number, damping coefficients (µ), and force amplitude (K), leading to significant changes in fundamental frequencies of the stiffened doubly curved shallow shell. Also, increasing of parameter σ, causes to increase the peak of response amplitude.

Bibliometric Analysis and Review of Literature on the Relationship Between Voice Production and Bilingualism.

The spoken language may influence the way we produce our voice. Therefore, speak more than one language could affect voice production. However, there is limited evidence on the relationship between voice production and bilingualism. To characterize the relationship between bilingualism and voice production determined by means of voice acoustic parameters and voice perception. A review of literature was performed using four computerized databases. The keywords used were voice, bilingualism, and multilingualism. Relevant data were extracted from the publications on country and year of study, participants, sample size, characterization of voice production (acoustics, perceptual), and languages. A bibliometric analysis was performed for co-occurrence analysis. Quality assessment was conducted with the EPHPP tool. A total of 10 publications met our inclusion criteria. Nine of the articles compared English productions with another language. Included studies reported changes in fundamental frequency between English and Spanish, Cantonese Chinese, Mandarin, Russian, Finnish, Arabic, Korean, Welsh, and Hebrew. The co-occurrence analysis shows that fundamental frequency is the most reported parameter, and English is the most compared language among studies including bilingual speakers. Speaking a second language influences voice production determined by voice acoustic parameters, such as fundamental frequency. Therefore, language may be an important factor to take into consideration when planning assessment and intervention programs on the field of voice.

Numerical calculation of the Lorentz force detuning and the pressure sensitivity for the HL-LHC crab cavity

Crab cavities are fundamental components of the HL-LHC upgrade project. These Radio Frequency cavities, operated at the appropriate frequency, ‘tilt’ the proton bunches to increase the luminosity at the collision points IP1 (ATLAS) and IP5 (CMS). Two different superconducting crab cavities were developed: RF Dipole (RFD) for horizontal deflection and Double Quarter Wave (DQW) for vertical deflection. During operation, the cavity walls are deformed due to the loading conditions. This deformation changes the electro-magnetic field inside the cavity and consequently its RF frequency. In the present study, the numerical evaluation of the Lorentz Force Detuning (LFD) and the Pressure Sensitivity (PS) of the DQW cavity, using COMSOL Multiphysics, is presented. The LFD is the fundamental frequency change of the cavity due to the electro-magnetic forces acting on its walls, while the PS is the frequency shift when the cavity is subjected to pressure fluctuations of the helium bath. Finally, a comparison with the results measured during the cold test of the manufactured cavities, and with the previous simulations results obtained for the RFD cavity is done.

Pitch Variation Skills in Cantonese Speakers With Apraxia of Speech After Stroke: Preliminary Findings of Acoustic Analyses.

Literature on apraxia of speech (AOS) in Chinese speakers is sparse compared to the English literature. This study aims to examine the pitch variation skills of Cantonese adults with AOS poststroke in terms of perceptual tone accuracy, acoustic fundamental frequency (fo) changes, and repetition durations on items with different syllable structures, lexical status, and tone syllables in various positions in a sequencing context. Six Cantonese adults with AOS poststroke (AOS group), six adults without AOS poststroke (nAOS group), and six healthy controls (HC group) performed the tone sequencing task (TST), which was adapted from oral diadochokinetic tasks, with three different tone syllables. Tone accuracy, fo values across 10 time points, and acoustic repetition durations were compared within and between the groups. The AOS group produced significantly lower tone accuracy and different fo changes on the three Cantonese tone syllables compared with the control groups and significantly longer repetition durations than the HC group. The AOS group showed more difficulty with the tone syllables with the consonant-vowel structure, while a priming effect was observed on the T2 (high-rising) syllables with lexical meanings. A unique lowering of fo in the final syllable of the trisyllabic items was observed only in the AOS group. The AOS group showed degraded pitch variation skills. The effects of the three linguistic elements were discussed. Future investigations are called for to adapt the TST in other tonal languages to determine if degraded pitch variation skills are present in other tonal language speakers with AOS.

Influences of fatigue stiffness degradation of in-service concrete T-beams on natural vibration frequency

ABSTRACT In order to obtain the fatigue stiffness degradation law of in-service concrete T-beam and carry out fatigue life prediction, a dual-stage stiffness degradation model considering cracks was established for T-beams and formulas for calculating the fundamental frequency of damaged concrete T-beams were deduced based on relevant theories of damage mechanics. The developed model aimed to investigate the influences of the fatigue stiffness degradation of in-service concrete T-beams on the natural vibration frequency of structures. A fatigue test was conducted for full-scale test beams to examine the crack development and fundamental frequency change law of structures during the fatigue process. Based on a full scale model of 10 m reinforced concrete T-beams, static and fatigue failure tests were carried out to obtain the evolution law of fatigue residual stiffness with load times. Fatigue damage coefficient D and stiffness degradation coefficient k were introduced to establish the fatigue life prediction model of T-beams in service. In line with the related test data and fundamental frequency formulas, stiffness updating methods were put forward for the concrete T-beam finite element models. By comparing the calculated value and test value of the natural vibration frequency of structures, the relative error was estimated to be within 6%. This verified the accuracy and reliability of the fundamental frequency calculation formulas and the updated finite element models. The research results can be used as a reference for the precise simulation of the fatigue damage finite element models of concrete T-beams. Finally, a method for life prediction of in-service reinforced concrete beam Bridges is proposed, and relevant research results can provide theoretical support for the study of life prediction of such Bridges.

Modeling, design, and optimization of a dielectric elastomer acoustic liner

The modeling, design, and optimization of an embedded dielectric elastomer (DE) membrane acoustic liner is considered. The acoustic impedance of the liner is modified when the DE is subjected to voltage, resulting in a reduction of the in-plane stress. A lumped element model of an embedded dielectric elastomer acoustic liner is derived and validated in a normal incidence impedance tube and is subsequently used to optimize its performance. The optimization cost functions include (1) maximization of the average absorption coefficient over a targeted frequency range, 400 – 1600 Hz and (2) maximization of the change in the liner fundamental resonance frequency when the membrane is activated. Good agreement between measured and predicted absorption is observed. Tuning of the resonant frequency requires a numerical solution for resonance using the imaginary part of the impedance, since a simple analytical expression for resonance cannot be derived due to the complex coupling between the acoustics of the liner and the electro-mechanics of the DE membrane. Nonetheless, resonant frequency shifts predicted with the lumped element model compare favorably to those measured with the activated liner sample, with a shift of 213 Hz.

Angular magnetic field dependence of a doubly clamped magnetoelectric resonator

Angular dependence of magnetic field response of fully suspended resonant microelectromechanical double-clamped magnetoelectric beams was investigated as the basis for a vector magnetometer utilizing the magnetically induced change in fundamental resonance frequency. Strain-coupled magnetostrictive iron cobalt (FeCo) and piezoelectric aluminum nitride layers together constitute a magnetoelectric heterostructure with a high magnetic field sensitivity of 70 Hz/mT along the beam axis and a transfer function of 47 V/T at 10 Hz. The fundamental frequency shift to an external magnetic field is found to be strongly anisotropic with a relative variation of more than 3% between perpendicular and parallel field orientations with respect to the long axis of the beam at a field of 100 mT. This design can form the basis for an on-chip high sensitivity vector magnetometer operating with ultra-low power when multiplexed with two or more resonators.

The Efficacy of the Manual Circumlaryngeal Therapy for Muscle Tension Dysphonia: A Systematic Review and Meta-analysis.

Muscle tension dysphonia (MTD) is the most common functional voice disorder. Behavioral voice therapy is the front-line treatment for MTD, and laryngeal manual therapy may be a part of this treatment. The objective of this study was to investigate the effect of manual circumlaryngeal therapy (MCT) on acoustic markers of voice quality (jitter, shimmer, and harmonics-to-noise ratio) and vocal function (fundamental frequency) through a systematic review with meta-analysis. Four databases were searched from inception to December 2022, and a manual search was performed. The PRISMA extension statement for reporting systematic reviews incorporating a meta-analysis of health care interventions was applied, and a random effects model was used for the meta-analyses. We identified 6 eligible studies from 30 studies (without duplicates). The MCT approach was highly effective on acoustics with large effect sizes (Cohen's d > 0.8). Significant improvements were obtained in jitter in percent (mean difference of -.58; 95% CI -1.00 to 0.16), shimmer in percent (mean difference of -5.66; 95% CI -8.16 to 3.17), and harmonics-to-noise ratio in dB (mean difference of 4.65; 95% CI 1.90-7.41), with the latter two measurements continuing to be significantly improved by MCT when measurement variability is considered. The efficacy of MCT for MTD was confirmed in most clinical studies by assessing jitter, shimmer, and harmonics-to-noise ratio related to voice quality. The effects of MCT on the fundamental frequency changes could not be verified. Further contributions of high-quality randomized control trials are needed to support evidence-based practice in laryngology. Laryngoscope, 134:18-26, 2024.

Modeling the influence of the extrinsic musculature on phonation.

Neck muscles play important roles in various physiological tasks, including swallowing, head stabilization, and phonation. The mechanisms by which neck muscles influence phonation are not well understood, with conflicting reports on the change in fundamental frequency for ostensibly the same neck muscle activation scenarios. In this work, we introduce a reduced-order muscle-controlled vocal fold model, comprising both intrinsic muscle control and extrinsic muscle effects. The model predicts that when the neck muscles pull the thyroid cartilage in the superior-anterior direction (with a sufficiently large anterior component), inferior direction, or inferior-anterior direction, tension in the vocal folds increases, leading to fundamental frequency rise during sustained phonation. On the other hand, pulling in the superior direction, superior-posterior direction, or inferior-posterior direction (with a sufficiently large posterior component) tends to decrease vocal fold tension and phonation fundamental frequency. Varying the pulling force location alters the posture and phonation biomechanics, depending on the force direction. These findings suggest potential roles of particular neck muscles in modulating phonation fundamental frequency, with implications for vocal hyperfunction.

Peripheral Intravenous Waveform Analysis Responsiveness to Subclinical Hemorrhage in a Rat Model.

Early detection and quantification of perioperative hemorrhage remains challenging. Peripheral intravenous waveform analysis (PIVA) is a novel method that uses a standard intravenous catheter to detect interval hemorrhage. We hypothesize that subclinical blood loss of 2% of the estimated blood volume (EBV) in a rat model of hemorrhage is associated with significant changes in PIVA. Secondarily, we will compare PIVA association with volume loss to other static, invasive, and dynamic markers. Eleven male Sprague Dawley rats were anesthetized and mechanically ventilated. A total of 20% of the EBV was removed over ten 5 minute-intervals. The peripheral intravenous pressure waveform was continuously transduced via a 22-G angiocatheter in the saphenous vein and analyzed using MATLAB. Mean arterial pressure (MAP) and central venous pressure (CVP) were continuously monitored. Cardiac output (CO), right ventricular diameter (RVd), and left ventricular end-diastolic area (LVEDA) were evaluated via transthoracic echocardiogram using the short axis left ventricular view. Dynamic markers such as pulse pressure variation (PPV) were calculated from the arterial waveform. The primary outcome was change in the first fundamental frequency (F1) of the venous waveform, which was assessed using analysis of variance (ANOVA). Mean F1 at each blood loss interval was compared to the mean at the subsequent interval. Additionally, the strength of the association between blood loss and F1 and each other marker was quantified using the marginal R2 in a linear mixed-effects model. PIVA derived mean F1 decreased significantly after hemorrhage of only 2% of the EBV, from 0.17 to 0.11 mm Hg, P = .001, 95% confidence interval (CI) of difference in means 0.02 to 0.10, and decreased significantly from the prior hemorrhage interval at 4%, 6%, 8%, 10%, and 12%. Log F1 demonstrated a marginal R2 value of 0.57 (95% CI 0.40-0.73), followed by PPV 0.41 (0.28-0.56) and CO 0.39 (0.26-0.58). MAP, LVEDA, and systolic pressure variation displayed R2 values of 0.31, and the remaining predictors had R2 values ≤0.2. The difference in log F1 R2 was not significant when compared to PPV 0.16 (95% CI -0.07 to 0.38), CO 0.18 (-0.06 to 0.04), or MAP 0.25 (-0.01 to 0.49) but was significant for the remaining markers. The mean F1 amplitude of PIVA was significantly associated with subclinical blood loss and most strongly associated with blood volume among the markers considered. This study demonstrates feasibility of a minimally invasive, low-cost method for monitoring perioperative blood loss.

Indexing Cognitive Resource Usage for Acquisition of Initial Voice Therapy Targets.

The purpose of this study was to index cognitive resource usage for acquisition of initial targets of two common voice therapy techniques (resonant voice therapy [RVT] and conversation training therapy [CTT]) based on the theorized depletion effect (i.e., when an initial task requiring high cognitive load leads to poorer performance on a subsequent task). Eleven vocally healthy participants, ages 23-41 years, read aloud the Rainbow Passage and produced consonant-vowel resonant targets (/mi, ma, mu/) followed by a baseline computerized Stroop task and a 15-min washout. Following this baseline period, participants watched and interacted with two videos instructing them in RVT or CTT initial targets. After viewing each video and practicing the associated vocal skills, participants rated the degree of mental effort required to engage in the target vocal technique on a modified Borg scale. Participants recorded their attempts at RVT on /mi, ma, mu/ and CTT on the Rainbow Passage, which were later rated by three voice-specialized speech-language pathologists as to how representative they were of each respective target technique. Changes in fundamental frequency and average auditory-perceptual ratings from baseline were examined to determine if participants adjusted their technique from RVT and CTT baseline to acquisition. Performance on the Stroop task was, on average, worse post CTT than post RVT, but both post-CTT and post-RVT Stroop scores were poorer than baseline. These results suggest that both treatment techniques taxed cognitive resources but that CTT was more cognitively taxing than RVT. However, despite differences in raw averages, no statistically significant differences were found between the baseline, post-CTT, and post-RVT Stroop scores, likely due to the small sample size. Participant ratings of mental effort for CTT and RVT were statistically similar. Likewise, poorer post-RVT Stroop scores were associated with participants' greater perceived mental effort with RVT acquisition, but there was no significant association between mental effort ratings for CTT acquisition and post-CTT Stroop scores. Significantly higher fundamental frequency and perceived ratings of the accuracy of technique from baseline to acquisition for both CTT and RVT were found, providing evidence of vocal behavior changes as a result of each technique. Brief exposure to initial treatment tasks in CTT is more cognitively depleting than initial RVT tasks. Results also indicate that vocally healthy participants are able to make a voice change in response to a brief therapy prompt. Finally, participant-rated measures of mental effort and secondary measures of cognitive depletion do not always correlate.

A Voice-Producing System With Naturalness and Variable Multi-Frequency Vocalization for Patients Who Have Undergone Laryngectomy

Patients with advanced laryngeal cancer usually mist undergo total laryngectomy, which causes communication difficulties. Several voice-producing devices have been developed to assist such patients in restoring their ability to speak. However, these devices produce monotonous sounds and require hand-held operation. A novel electronic voice-producing system was thus proposed to assist patients with laryngectomy in improving their speech performance. By imitating normal human speech, the proposed system enables the adjustment of the fundamental frequency of generated sound according to changes in lung pressure through exhalation; this enables different tones to be produced. Moreover, the proposed system is wearable and thus convenient to use. According to the experimental results, the proposed system provides changes in fundamental frequency corresponding to different tones and sentences in human speech, and outperforms existing devices in speech performance. A novel voice-producing system was proposed and implemented to assist patients who had undergone laryngectomy to resume basic communication activities.

An Adaptive-Frequency Harmonic Suppression Strategy Based on Vector Reconstruction for Current Measurement Error of PMSM Drives

The errors of gain and offset caused by the current sensor measurement can lead to the first and second harmonics in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis currents of the permanent magnet synchronous motor (PMSM) drives. An adaptive-frequency harmonic suppression strategy based on the vector reconstruction for current measurement error is proposed. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis current vector is recoordinate transformed using the division-frequency position as the transformation matrix angle. Thus, the frequency of the fundamental component can be decoupled from that of the harmonics in the current vector. In this way, the single-frequency harmonic suppressor can be established in the reconstructed coordinate frame. The current vector error is converged by adaptively adjusting the filtering weight and frequency so as to eliminate the harmonics. In view of the change of fundamental frequency, the variable step of the convergence is used to obtain the ideal filtering effect at different speeds and reduce the negative impact of current sensor measurement errors. The effectiveness of the proposed method is verified on the 11.7-kW PMSM drive platform.

Relative pitch representations and invariance to timbre

Information in speech and music is often conveyed through changes in fundamental frequency (f0), perceived by humans as “relative pitch”. Relative pitch judgments are complicated by two facts. First, sounds can simultaneously vary in timbre due to filtering imposed by a vocal tract or instrument body. Second, relative pitch can be extracted in two ways: by measuring changes in constituent frequency components from one sound to another, or by estimating the f0 of each sound and comparing the estimates. We examined the effects of timbral differences on relative pitch judgments, and whether any invariance to timbre depends on whether judgments are based on constituent frequencies or their f0. Listeners performed up/down and interval discrimination tasks with pairs of spoken vowels, instrument notes, or synthetic tones, synthesized to be either harmonic or inharmonic. Inharmonic sounds lack a well-defined f0, such that relative pitch must be extracted from changes in individual frequencies. Pitch judgments were less accurate when vowels/instruments were different compared to when they were the same, and were biased by the associated timbre differences. However, this bias was similar for harmonic and inharmonic sounds, and was observed even in conditions where judgments of harmonic sounds were based on f0 representations. Relative pitch judgments are thus not invariant to timbre, even when timbral variation is naturalistic, and when such judgments are based on representations of f0.

Support condition monitoring of monopile-supported offshore wind turbines in layered soil based on model updating

Monopile-supported offshore wind turbines (OWTs) are dynamically sensitive structures whose fundamental frequencies may be close to those of environmental and turbine-related excitations. The changes in fundamental frequencies caused by pile-soil interaction (PSI) may result in unwanted resonance and serious O&M (Operation and Maintenance) issues, which have been identified as major challenges in the research field. Therefore, a novel model updating framework with an implicit objective function is proposed to monitor both the stiffness and damping variation of the OWT system based on the measured vibration characteristics, which is further verified by laboratory tests. In particular, layered soil was considered in the tests to simulate the practical soil conditions of Chinese seas. Different pile lengths were introduced to consider the long-term PSI effects for rigid piles and slender piles. The results showed that the variation in the fundamental frequency is significantly reduced in layered soil compared with the pure sand scenario. For the OWT systems in layered soil, the variation in foundation stiffness is negatively related to the burial depth under cyclic loading. The proposed model updating framework is proven reliable for support condition monitoring of OWT systems in complicated soil conditions.

Effect of Voice Projection Training on Acoustic and Auditory-Perceptual Characteristics of Voice in Tamil-Speaking Imams

Imams are professional voice users at risk of developing voice problems. Speech-Language Pathologists need to provide intervention programs to target risk factors associated with voice disorders and improve the voice quality of Imams. However, studies examining the effect of vocal training for Imams are limited in the literature. This study attempted to document the acoustic and auditory-perceptual changes in the voices of Tamil-speaking Imams with a voice projection training program. Eleven Tamil-speaking Imams participated in a voice projection training program. Voice samples were recorded at four specific time points before, during, and after the voice projection training. These recordings were subjected to various acoustic analyses (AVQI, Dr Speech, and MDVP) and auditory-perceptual analysis (CAPE-V) to determine the changes with the voice projection training. Auditory-Perceptual analysis carried out by five experienced SLPs suggested significant changes in the voice quality of the participants with voice projection training. High inter-rater reliability was observed across the judges as well. We observed positive changes in several acoustic measures indicated within AVQI, Dr Speech, and MDVP software. These primarily included changes in fundamental frequency, noise related measures (HNR, SNR), and perturbation measures. Voice projection training positively impacts the acoustic and auditory-perceptual characteristics of the voices of Tamil-speaking Imams.

Empirical Evaluation of the Role of Vocal Fold Collision on Relative Fundamental Frequency in Voicing Offset

Relative fundamental frequency (RFF) is an acoustic measure of changes in fundamental frequency during voicing transitions. The physiological mechanisms underlying RFF remain unclear. Recent modeling suggests that changes in RFF during voicing offset are due to decreases in overall system stiffness as a direct result of the cessation of vocal fold collision. To evaluate this finding empirically, here we examined whether variable timing between the end of vocal fold collision and the final voicing cycle used to calculate RFF explained the variability in RFF across individual voicing offset utterances. RFF during voicing offset was calculated from /ifi/ utterances produced by 35 participants under endoscopy, with and without vocal effort. RFF was calculated via two methods, in which utterances were aligned by (1) the end of vocal fold collision, or (2) the end of voicing. Analyses of variance were used to determine the effects of vocal effort and RFF method on the mean and standard deviation of RFF. Aligning by vocal fold collision resulted in statistically significantly lower standard deviations. RFF means were statistically higher using the collision method; however, the degree of vocal effort was statistically significant regardless of the method. These results provide empirical evidence to support that decreases in RFF during voicing offset are a result of decreases in system stiffness due to termination of vocal fold collision.