Fundamental Frequency Variation Research Articles

How Much Does the Dynamic F0 Curve Affect the Expression of Emotion in Utterances?

The modulation of vocal elements, such as pitch, loudness, and duration, plays a crucial role in conveying both linguistic information and the speaker’s emotional state. While acoustic features like fundamental frequency (F0) variability have been widely studied in emotional speech analysis, accurately classifying emotion remains challenging due to the complex and dynamic nature of vocal expressions. Traditional analytical methods often oversimplify these dynamics, potentially overlooking intricate patterns indicative of specific emotions. This study examines the influences of emotion and temporal variation on dynamic F0 contours in the analytical framework, utilizing a dataset valuable for its diverse emotional expressions. However, the analysis is constrained by the limited variety of sentences employed, which may affect the generalizability of the findings to broader linguistic contexts. We utilized the Ryerson Audio-Visual Database of Emotional Speech and Song (RAVDESS), focusing on eight distinct emotional states performed by 24 professional actors. Sonorant segments were extracted, and F0 measurements were converted into semitones relative to a 100 Hz baseline to standardize pitch variations. By employing Generalized Additive Mixed Models (GAMMs), we modeled non-linear trajectories of F0 contours over time, accounting for fixed effects (emotions) and random effects (individual speaker variability). Our analysis revealed that incorporating emotion-specific, non-linear time effects and individual speaker differences significantly improved the model’s explanatory power, ultimately explaining up to 66.5% of the variance in the F0. The inclusion of random smooths for time within speakers captured individual temporal modulation patterns, providing a more accurate representation of emotional speech dynamics. The results demonstrate that dynamic modeling of F0 contours using GAMMs enhances the accuracy of emotion classification in speech. This approach captures the nuanced pitch patterns associated with different emotions and accounts for individual variability among speakers. The findings contribute to a deeper understanding of the vocal expression of emotions and offer valuable insights for advancing speech emotion recognition systems.

Analysis of Speech Features in Alzheimer's Disease with Machine Learning: A Case-Control Study.

Changes in the speech and language of patients with Alzheimer's disease (AD) have been reported. Using machine learning to characterize these irregularities may contribute to the early, non-invasive diagnosis of AD. We conducted cognitive function assessments, including the Mini-Mental State Examination, with 83 patients with AD and 75 healthy elderly participants, and recorded pre- and post-assessment conversations to evaluate participants' speech. We analyzed the characteristics of the spectrum, intensity, fundamental frequency, and minute temporal variation (∆) of the intensity and fundamental frequency of the speech and compared them between patients with AD and healthy participants. Additionally, we evaluated the performance of the speech features that differed between the two groups as single explanatory variables. We found significant differences in almost all elements of the speech spectrum between the two groups. Regarding the intensity, we found significant differences in all the factors except for the standard deviation between the two groups. In the performance evaluation, the areas under the curve revealed by logistic regression analysis were higher for the center of gravity (0.908 ± 0.036), mean skewness (0.904 ± 0.023), kurtosis (0.932 ± 0.023), and standard deviation (0.977 ± 0.012) of the spectra. This study used machine learning to reveal speech features of patients diagnosed with AD in comparison with healthy elderly people. Significant differences were found between the two groups in all components of the spectrum, paving the way for early non-invasive diagnosis of AD in the future.

Predicting the intelligibility of Mandarin Chinese with manipulated and intact tonal information for normal-hearing listeners.

Objective indices for predicting speech intelligibility offer a quick and convenient alternative to behavioral measures of speech intelligibility. However, most such indices are designed for a specific language, such as English, and they do not take adequate account of tonal information in speech when applied to languages like Mandarin Chinese (hereafter called Mandarin) for which the patterns of fundamental frequency (F0) variation play an important role in distinguishing speech sounds with similar phonetic content. To address this, two experiments with normal-hearing listeners were conducted examining: (1) The impact of manipulations of tonal information on the intelligibility of Mandarin sentences presented in speech-shaped noise (SSN) at several signal-to-noise ratios (SNRs); (2) The intelligibility of Mandarin sentences with intact tonal information presented in SSN, pink noise, and babble at several SNRs. The outcomes were not correctly predicted by the Hearing Aid Speech Perception Index (HASPI-V1). A new intelligibility metric was developed that used one acoustic feature from HASPI-V1 plus Hilbert time envelope and temporal fine structure information from multiple frequency bands. For the new metric, the Pearson correlation between obtained and predicted intelligibility was 0.923 and the root mean square error was 0.119. The new metric provides a potential tool for evaluating Mandarin intelligibility.

Investigation of mothers' elicited infant-directed speech and singing for preterm infants.

Mother's voice is a salient auditory stimulus commonly experienced during early development; after birth, characteristic acoustic modulations of mothers' infant-directed speech (IDSpeech) and singing (IDSinging) contribute to neurodevelopment. For preterm infants, early separation leads to decreased exposure to mother's voice; the impact on maternal ability to produce IDSpeech/IDSinging and infant perception of mother's voice is unknown. Fifty mother/preterm-infant dyads were enrolled in this prospective cohort study. Forty-four mothers recorded Twinkle, Twinkle Little Star in coached adult-directed speech (ADSpeech), IDSpeech, and IDSinging. Between 34.0-36.9w CGA, infants underwent high-density EEG during exposure to their mother's voice recordings. Acoustic features of mothers' voice and infant cortical response were analyzed and correlated. Acoustic features of recorded maternal ADSpeech, IDSpeech, and IDSinging were significantly different. In 33 infants with EEG, mean fundamental frequency and speech production rate (SPR) variability correlated with infant responses to ADSpeech; SPR and SPR variability correlated with IDSpeech; SPR correlated with IDSinging. Correlations were found at differing scalp locations for speech versus singing. Mothers of hospitalized preterm infants differentially modulate their voice during coached recorded language; features can then be differentiated by their preterm infants thus presenting opportunities for targeted interventions when parents cannot be present. Mothers of preterm infants can record their voice with acoustically quantifiable characteristics of infant-directed singing and speech, even when not at their infant's bedside. Recorded adult- and infant-directed speech stimuli are differentially processed in the brains of hospitalized preterm infants. The ability for mothers to create acoustically-distinct infant-directed speech in the absence of their infant may be driven by coaching to achieve an approximated sense of connection with their infant.

SVPWM‐Based Algorithm for Reduced THD and Switching Losses Under Varying Fundamental Frequency and Load in a VSI

ABSTRACTThe present study explores the influence exerted by various pulse width modulation (PWM) techniques upon harmonic distortion and switching losses of a voltage source inverter. In the context of this inquiry, a generalized algorithm for variable frequency operations, inspired by continuous and discontinuous PWM is outlined in this article. The algorithm is explicitly formulated as a function of fundamental frequency and the load power factor angle with the objective of minimizing total harmonic distortion (THD) and switching losses within a specified frequency range. The algorithm is segmented into various regions of frequency, guided by the theory that each region corresponds to a distinct PWM technique that yields reduced harmonic distortion. In this article, a minimum switching loss algorithm is introduced and implemented using both BCPWM and ABCPWM techniques. The algorithm is specifically designed to minimize switching losses across the entire range of load power factor angles. The integration of switching loss algorithm with the selection of the optimal PWM technique across different frequency ranges results in reduced switching losses and harmonic distortion. This leads to a comprehensive PWM algorithm that efficiently reduces both THD and switching losses during dynamic frequency and load changes. Experimental and theoretical evidences demonstrate the efficacy of the proposed algorithm in attaining minimum harmonic distortion and reduced switching loss operation during variations in fundamental frequency and load.

Vocal Emotion Perception in Children Using Cochlear Implant.

The significance of emotional prosody in social communication is well-established, yet research on emotion perception among cochlear implant (CI) users is less extensive. This study aims to explore vocal emotion perception in children using CI and bimodal hearing devices and compare them with their normal hearing (NH) peers. The study involved children aged 4-10 years with unilateral CI and contralateral hearing aid (HA), matched with NH peers by gender and listening age. Children were selected using snowball sampling for the CI group and purposive sampling for the NH group. Vocal emotion perception was assessed for semantically neutral sentences in "happy," "sad," and "angry" emotions using a 3 alternate forced choice test. The NH group demonstrated significantly superior emotion perception (P=.002) compared to the CI group. Both groups accurately identified the "happy" emotion. However, the NH group had higher scores for the "angry" emotion compared to the "sad" emotion, while the CI group showed better scores for "sad" than "angry" emotion. Bimodal hearing devices improved recognition of "sad"and "angry" emotions, with a decrease in confusion percentages. The unbiased hit (Hu) value provided more substantial insight than the hit score. Bimodal hearing devices enhance the perception of "sad" and "angry" vocal emotions compared to using a CI alone, likely due to the HA providing the temporal fine structure cues, thereby better representing fundamental frequency variations. Children with unilateral CI benefit significantly in the perception of emotions by using a HA in the contralateral ear, aiding in better socio-emotional development.

What is airflow vibrato?

Vocal vibrato has a number of manifestations. Typically vibrato is first thought of as a variation in fundamental frequency (fo), and secondarily as a variation in intensity and sound quality. Other variations that accompany these three types of vibrato include movement of throat structures (changes in larynx height, alterations in arytenoid adduction, pharyngeal wall movement, tongue movement, etc.), and especially muscle contraction variations that accompany all mentioned vibrato types.

Comparison of Acoustic Parameters of Voice and Speech According to Vowel Type and Suicidal Risk in Adolescents

Globally, suicide prevention and understanding suicidal behavior represent significant health challenges. The predictive potential of voice, speech, and language appears as a promising solution to the difficulty in assessment. ObjectiveTo analyze variations in acoustic parameters in voice and speech based on vowel types according to different levels of suicidal risk among adolescents in a text reading task. MethodologyCross-sectional analytical design using non-probabilistic sampling. Our sample comprised 98 adolescents aged 14 to 19, undergoing voice acoustic assessment, along with suicidal ideation determination through the Okasha Suicidality Scale and Beck Depression Inventory. Acoustic analysis of recordings was conducted using Praat for phonetic research, Python program, Focusrite interface, and microphone to register voice and speech acoustic parameters such as Fundamental Frequency, Jitter, and Formants. Subsequently, data from adolescents with and without suicidal risk were compared. ResultsSignificant differences were observed between suicidal and non-suicidal adolescents in several acoustic aspects, especially in females in fundamental frequency (F0), signal-to-noise ratio (HNRdB) and temporal variability measured by jitter and standard deviation. In mens, differences were found in F0 and HNRdB (p < 0.05). ConclusionThis study demonstrated statistically significant variations in various voice acoustic parameters among adolescents with and without suicidal risk. These findings underscore the potential relevance of voice and speech as markers for suicidal risk.

Effects of testosterone on speech production and perception: Linking hormone levels in males to vocal cues and female voice attractiveness ratings

This study sets out to investigate the potential effect of males’ testosterone level on speech production and speech perception. Regarding speech production, we investigate intra- and inter-individual variation in mean fundamental frequency (fo) and formant frequencies and highlight the potential interacting effect of another hormone, i.e. cortisol. In addition, we investigate the influence of different speech materials on the relationship between testosterone and speech production. Regarding speech perception, we investigate the potential effect of individual differences in males’ testosterone level on ratings of attractiveness of female voices.In the production study, data is gathered from 30 healthy adult males ranging from 19 to 27 years (mean age: 22.4, SD: 2.2) who recorded their voices and provided saliva samples at 9 am, 12 noon and 3 pm on a single day. Speech material consists of sustained vowels, counting, read speech and a free description of pictures. Biological measures comprise speakers’ height, grip strength, and hormone levels (testosterone and cortisol). In the perception study, participants were asked to rate the attractiveness of female voice stimuli (sentence stimulus, same-speaker pairs) that were manipulated in three steps regarding mean fo and formant frequencies.Regarding speech production, our results show that testosterone affected mean fo (but not formants) both within and between speakers. This relationship was weakened in speakers with high cortisol levels and depended on the speech material. Regarding speech perception, we found female stimuli with higher mean fo and formants to be rated as sounding more attractive than stimuli with lower mean fo and formants. Moreover, listeners with low testosterone showed an increased sensitivity to vocal cues of female attractiveness.While our results of the production study support earlier findings of a relationship between testosterone and mean fo in males (which is mediated by cortisol), they also highlight the relevance of the speech material: The effect of testosterone was strongest in sustained vowels, potentially due to a strengthened effect of hormones on physiologically strongly influenced tasks such as sustained vowels in contrast to more free speech tasks such as a picture description. The perception study is the first to show an effect of males’ testosterone level on female attractiveness ratings using voice stimuli.

Mapping acoustic characteristics of emotional prosody in Mandarin disyllabic words: A machine-learning approach

This study conducted an acoustic-prosodic mapping analysis of emotional prosody in Mandarin Chinese. It utilized a validated audiometry corpus with 450 disyllabic words. The spoken words covered five basic emotions produced by a female speaker: angry, sad, happy, fearful, and neutral. A machine-learning approach was adopted to map key acoustic-prosodic features for Mandarin emotional vocalization. The results revealed distinctive acoustic profiles for each emotion, highlighting variations in fundamental frequency, intensity, speaking rate, and voice quality. Emotional utterances consistently exhibited higher mean F0 values than neutral expressions. Fear displayed the highest crest in F0. Angry and happy utterances showed greater vocal intensity and a faster speaking rate compared to fearful and sad expressions. While anger was associated with a creaky voice quality, sadness corresponded with a breathier voice quality. The current findings are limited with the use of the single-speaker corpus. Ongoing efforts aim to expand the corpus with more speakers to test the generalizability and scalability of the analysis approach for subsequent investigations.

Investigation on the dynamic characteristics of anchor rods considering size effect and pull-out loads based on IIR-FDM

When the surrounding rock of tunnel anchor bars has boundaries, the signals obtained from non-destructive testing (NDT) of anchor rods will be simultaneously affected by size effects and pull-out loads, leading to potential misinterpretation of the test results. In order to accurately assess the anchorage quality of anchor rods under this interference, NDT and numerical simulations of anchor rods subjected to different anchorage quality were conducted under the influence of size effects and pull-out loads. A signal filtering method, which combines the infinite impulse response-finite difference method, was proposed for identify the impact of size effects. The study analyzed the variations in wave velocity and fundamental frequency of anchor rods with anchorage defects and intact anchor rods under the influence of size effects and pull-out loads. The results indicate that the IIR-FDM method, in comparison to the traditional wavelet method, provides better agreement between the calculated wave velocities and existing findings. With the increase of size effect, the wave velocity and amplitude ratio of the anchor rods decrease, and the fundamental frequency increases first and then decreases. As the working load on the anchor rods increases, the wave velocity initially decreases, then rises, while the fundamental frequency initially increases and then experiences a slight decrease. The presence of anchorage defect results in an increase in the wave velocity and amplitude ratio of the anchor rods, while causing a decrease in the fundamental frequency. This effect of defects on wave velocity and fundamental frequency is more pronounced at lower loads. The wave velocity after IIR-FDM processing has a small error with the simulated wave velocity, indicating the reliability of the processing method.

A novel semi-empirical approach to non-destructively evaluate the effect of infills on frame buildings

Masonry infilled frame (MIF) structures are commonly used as building system in many regions, and particularly in Latin American, Mediterranean, and Pacific countries, which are areas highly exposed to seismic events. It is well known that the influence of the infilled frames on the seismic response is affected by several sources of uncertainties which create unsafe unaccuracies in the seismic behaviour of a building. The use of existing complex models is an option which require a large number of specialized input values and data mostly obtained from in-situ destructive tests, thus making them infeasible in many practical cases. This research is a first attempt to provide an approach which provides prediction of the structural behaviour of a MIF with quantified uncertainty, and using as inputs values that can be obtained through a low-cost non-destructive test. The proposed method exploits the known interaction between the in-plane (IP) and out-of-plane (OoP) behaviour of the masonry wall by providing a semi-empirical model which predicts the IP stiffness of the MIF in terms of the measured OoP fundamental frequency. The semi-empirical approach has been nurtured with five experimental tests over one-fourth scale MIFs, where the OoP fundamental frequency variation has been obtained in terms of the IP deformation history. The results indicate that the proposed method can become a practical tool to experimentally quantify the contribution of the masonry infills of existing frame buildings, and also to theoretically predict it during design phase. However, a larger dataset of tests should be used on the calibration of the method before its application in real cases.

On the role of pauses – a qualitative and quantitative analysis of selected political speeches in the European Parliament

This paper presents an analysis of speech pauses occurring in selected political speeches, with a focus on both filled and silent types. The paper aims to highlight differences among pause categories in spoken language and assess potential gender differences. By analyzing speeches from male and female speakers in specific syntactic contexts, the paper reveals limited variations in fundamental frequency and pause duration. While certain subcategories exhibit slight differences in frequency, consistent patterns are lacking. Findings indicate that filled, hesitation, politeness, and perturbation pauses tend to be longer, whereas specification and personal stance pauses tend to have lower frequencies. Enumeration, opposition, and segmenting pauses strategically support a speaker's point, aligned with sentence structure. Investigating fundamental frequency trends before pauses demonstrates that a decrease in frequency signifies unit culmination, while an increase suggests non-final positions within units. The paper concludes that disparities exist among pause types, though differences between male and female speakers are generally minor. This emphasizes the need to consider multiple factors, including duration, frequency, and syntactic context, for comprehensive pause definitions. Overall, the paper provides insight into speech pause attributes, variations, and their significance in conveying meaning, thus enriching our understanding of speech patterns and communication strategies.

Context effects on duration, fundamental frequency, and intonation in human-directed domestic cat meows

In this study, we investigated the prosody of domestic cat meows produced in different contexts. Prosodic cues – i.e., variation in intonation, duration, voice quality and fundamental frequency – in humans as well as in nonhuman animals carry information about idiosyncratic traits of the signaller, including sex, age, and physical and mental state. The duration, fundamental frequency (F0) and intonation in a sample of 969 meows recorded in seven different contexts (i.e., cuddle, door, food, greeting, lifting, play, cat carrier) were analysed using linear mixed effects regression and generalized additive models. In this, we controlled for cat age and sex, as meows produced by old cats had lower mean F0 than those produced by young cats, and female cats produced meows with higher mean F0 than male cats. We found significant effects of context on duration and mean F0, but not on F0 range. Furthermore, the results showed that the intonation of meows produced by cats in a cat carrier displayed a falling pattern, while that of meows produced in cuddle and door contexts was relatively level, and that of meows produced in the other contexts consisted of combinations of rising and falling. The average slope of meows produced in cat carrier and play contexts was negative, while that of meows produced in the other contexts was positive. We argue that this prosodic variation reflects the cats’ mental or emotional state, because of valence and arousal differences associated with the various contexts that were included in the study. Further studies will need to confirm this. In addition, we also plan additional analyses of spectral and voice quality parameters in meows and other cat vocalisation types.

Recognition of Speech With Dynamic Pitch Manipulation in Noise: Effects of Manipulation Methods.

Dynamic pitch, which is defined as the variation in fundamental frequency in speech, is one of the acoustic cues that affect speech recognition in noise. Built on the evidence that a symmetrical manipulation of dynamic pitch led to poorer speech recognition, the present study examined the effect of an asymmetrical manipulation method on speech recognition in noise by younger and older adults. Speech recognition accuracy in noise was measured from younger adults with normal hearing in Experiment 1, and speech reception threshold (in dB SNR) from older adults with normal hearing to mild-moderate hearing loss in Experiment 2. The dynamic pitch contours of the speech stimuli were manipulated using both symmetrical and asymmetrical methods. Younger adults recognized speech better in noise with asymmetrical than symmetrical manipulation, and with weakened than strengthened dynamic pitch. A substantial amount of variability was observed in a group of older listeners. This variability was predominately predicted by the listeners' age but not hearing thresholds or their ability to perceive dynamic pitch in fluctuating noise. The asymmetrical manipulation of dynamic pitch had a less negative effect than the symmetrical manipulation. This effect also interacted with pitch-change direction. These findings suggest the influence of perceptual naturalness on speech recognition with signal modification. Directions for future research are also discussed.

Production of emotions conveyed by voice in Parkinson's disease: Association between variability of fundamental frequency and gray matter volumes of regions involved in emotional prosody.

Parkinson's disease (PD) is associated with impairment in producing emotions conveyed by voice which could depend on motor limitations of the vocal apparatus and/or alterations in emotional processing. This study explores the relationship between the standard deviation of fundamental frequency (F0SD) of emotional speech and the volume of specific gray matter regions. Fifteen PD patients and 15 healthy controls (HC) were asked to produce different emotions vocally elicited by reading short stories. For each vocal track, the F0SD was calculated as index of variability. All subjects underwent a structural magnetic resonance imaging and a voxel-based morphometry analysis. An ad hoc mask of brain regions implicated in emotional prosody was constructed to test the relationship between F0SD and the level of brain atrophy. PD patients showed lower F0SD values than HC in the expression of anger. Neuroimaging results showed brain atrophy in PD patients in a widespread bilateral network, including frontal areas, left cingulate cortex, parietal areas as well as occipital cortices. In the PD group, a positive correlation was observed between F0SD values of anger and volumes of the bilateral supramarginal gyrus, left thalamus, right inferior frontal gyrus, and amygdala. The lower F0SD values observed in PD patients in anger production are consistent with their lower ability to express anger effectively through voice compared to HC. Our data demonstrated the involvement of right-lateralized areas, such as the inferior frontal gyrus and amygdala, which are typically involved in emotional prosody. Disturbances in emotion processing might contribute to speech production deficits in PD, probably in addition to the motor impairment of the articulatory system. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Influence of vowels on note pitching in a cappella vocal quartet performance

This study aimed to investigate the relationship between the fundamental frequencies employed when singing different vowels on the same pitch for each member in turn of a professional soprano, alto, tenor, bass (SATB) a cappella vocal quartet in terms of the measured fundamental frequency during the production of a set of individual vowels within a four-part carrier phrase. This is an experimental singing production study on the tuning of vowels in the context of a cappella quartet singing. To facilitate this, one singer at a time in a professional a cappella vocal quartet changed the vowel they are singing on a single note concurrent with a consonant a cappella triad being sustained by the other three singers singing a fixed vowel. The first few bars of the a cappella anthem "If ye love me" by Thomas Tallis provided a carrier phrase that ended with a held chord on the chord on the word "me" by three singers against which the remaining singer produced a set of different vowels on their note of the chord. This is carried out for each of the four singers. The hypothesis being investigated is to remain accurately in-tune; fundamental frequency should be varied depending on the vowel being sung. Fundamental frequencies were measured using electrolaryngographs to ensure that there was no acoustic interference that could affect the accuracy of the fundamental frequency measurements if they were obtained from the audio output. The results provide clear evidence of changes being made to the fundamental frequencies of different vowels in an a cappella quartet context, and these changes confirm variations found elsewhere relating to the perceived pitches of different vowels. Measurable and consistent fundamental frequency variations occur when one part tunes different vowels against a reference chord sung by the other three singers in a choral quartet context on a fixed vowel. This has a direct consequence for tuning in a cappella choral music. The importance of carefully tuning individual notes for different vowels in a cappella choral singing requires focused listening to the pitches of the sounds being produced by the other singers in the choir. Usually, all parts are singing common vowels where it is important that the vowels are matched by being carefully blended together and tuning is aimed at being beat-free in just intonation. When compositions require parts to sing different vowels, both intrinsic (production related) and auditory (hearing related) pitch variations become relevant and challenge beat-free tuning.

Effect of clear speech on acoustic measures of dysprosody in Parkinson disease for different reading tasks

Purpose The purpose of the study was to determine the effect of clear speech instruction on acoustic measures of dysprosody between reading passages of differing linguistic content for speakers with and without Parkinson Disease (PD). Method Ten speakers with PD and 10 controls served as participants and read five simple and three standard reading stimuli twice. First, speakers read habitually and then following clear speech instruction. Acoustic measures of fundamental frequency variation (semitone standard deviation, STSD), articulation rate, and between-complex pause durations were calculated. Result Results indicated speakers with PD exhibited less fundamental frequency variation than controls across reading stimuli and instructions. All speakers exhibited lower STSD and longer between-complex pause durations for the standard compared to simple reading stimuli. For clear speech, all speakers reduced articulation rate and increased between-complex pause durations in both simple and standard reading stimuli. However, speakers with PD exhibited a significantly less robust reduction in articulation rate for clear speech than control speakers for all reading stimuli. Conclusion Linguistic content of reading stimuli contributes to differences in fundamental frequency variation and pause duration for all speakers. All speakers reduced articulation rate for clear speech compared to habitual instruction, but speakers with PD did so to a lesser extent than controls. Linguistic content of reading stimuli to examine dysprosody in PD should be considered for clinical application.

Whistle repertoire and structure reflect ecotype distinction of pantropical spotted dolphins in the Eastern Tropical Pacific

The pantropical spotted dolphin in the Eastern Tropical Pacific (ETP) is found in two genetically and phenotypically diverged ecotypes, coastal and offshore. These habitats have distinct acoustic characteristics, which can lead to the evolution of distinct acoustic communication. Whistles are sounds widely used by dolphins to mediate species and individual recognition and social interactions. Here, we study the whistle acoustic structure and repertoire diversity of offshore and coastal pantropical spotted dolphins. Our results show that there is significantly more within- and across-group variation in whistle fundamental frequency between ecotypes than between offshore groups and between coastal groups. A Random Forest classification analysis performed with an accuracy of 83.99% and identified duration, peak and minimum frequency as the most informative variables for distinguishing between ecotypes. Overall, coastal spotted dolphins produced significantly shorter whistles that were significantly lower in frequency (peak, minimum and maximum, and start and end) than offshore dolphins. Ecotypes produced whistle repertoires that were similar in diversity, but different in contour composition, with the coastal ecotype producing more upsweep whistles than offshore dolphins. The results of this study suggest that acoustic adaptations to coastal and offshore environments could be important contributors to intraspecific variation of dolphin whistle repertoires.

Interaction of Voice Onset Time with Vocal Hyperfunction and Voice Quality

The main aim of the present work was to investigate whether vocal hyperfunction (VH), perceptual voice quality (VQ), gender, and phonetic environment influence Voice Onset Time (VOT). The investigated group consisted of 30 adults, including 19 women (X = 46.1 ± 13.7 years) and 11 men (X = 47.5 ± 11.0 years), who had either phonotraumatic vocal hyperfunction (PVH) and non-phonotraumatic vocal hyperfunction (NPVH). VQ was judged considering the overall severity of dysphonia (OS) and the subcharacteristics of roughness, breathiness, and strain. Phonetic variables such as vowel stress, syllable stress, and mode of speech task were analyzed. Four samples of syllables with [p] plus vowel or diphthong were retrieved from CAPE-V sentences recordings. Acoustic analysis with Praat comprised VOT, mean fundamental frequency (fo), intensity (SPL dB(A)), and coefficient of variation of fundamental frequency (CV_fo %). VOT was significantly influenced by OS (p ≤ 0.001) but not by vocal VH condition (PVH versus NPVH) (p = 0.90). However, CV_fo was affected by the VH condition (p = 0.02). Gender effects were only found for mean fo (p ≤ 0.001) and SPL (p = 0.01). All VQ sub characteristics (OS, roughness, breathiness, and strain) correlated with VOT (p ≤ 0.001) and SPL (p ≤ 0.001) but not with fo. In summary, VOT was affected by voice quality, while it was not affected by vocal hyperfunction conditions. Therefore, VOT has the potential to objectively describe the onset of voicing in voice diagnostics, and may be one underlying objective characteristic of perceptual vocal quality.