Understanding the challenges faced by second language (L2) learners in lexical tone perception is crucial for effective language acquisition. This study investigates the impact of exaggerated acoustic properties on facilitating Mandarin tone learning for English speakers. Using synthesized tone stimuli, we systematically manipulated pitch contours through three key modifications: expanding the fundamental frequency (F0), increasing F0 (female voice), and extending the overall duration. Our objectives were to assess the influence of F0 expansion, higher F0, longer duration, and varied syllables on Mandarin tone learning and generalization. Participants engaged in a non-adaptive trial-by-trial tone identification task. Mixed-effects logistic regression modeling was used to analyze accuracy across learning phases, acoustic factors, and tones. Findings reveal improvements in accuracy from training to testing and generalization phases, indicating the effectiveness of perceptual training to tone perception for adult English speakers. Tone 1 emerged as the easiest to perceive, while Tone 3 posed the most challenge, consistent with established hierarchies of tonal acquisition difficulty. Analysis of acoustic factors highlighted tone-specific effects. Expanded F0 was beneficial for the identification of Tone 2 and Tone 3 but posed challenges for Tone 1 and Tone 4. Additionally, longer durations also exhibited varied effects across tones, aiding in the identification of Tone 3 and Tone 4 but hindering Tone 1 identification. The higher F0 was advantageous for Tone 2 but disadvantageous for Tone 3. Furthermore, the syllable ma facilitated the identification of Tone 1 and Tone 2 but not for Tone 3 and Tone 4. These findings enhance our understanding of the role of acoustic properties in L2 tone perception and have implications for the design of effective training programs for second language acquisition.

Given the bidirectional association between psychopathology and relationship distress, an in-depth understanding of couples\' interaction processes that contribute to psychopathology is needed. This study examined the interpersonal dynamics of vocally-encoded emotional arousal (fundamental frequency, f0) during couple conversations and their associations with depressive symptoms, anxiety symptoms, and relationship distress. Data from eight samples were pooled (N = 404 couples) to examine (a) overall trajectories of f0 across the interaction and (b) moment-by-moment intraindividual changes in and interpersonal reactivity to partners\' f0. Multilevel growth models and repeated-measures actor-partner interdependence models demonstrated that individuals with more severe depression showed more synchronizing reactivity to their partners\' f0 on a moment-by-moment basis, and their overall baseline level of f0 was lower. More severe relationship distress was associated with more steeply increasing trajectories of f0 and with greater synchronizing reactivity to partners\' f0. Relative differences in depressive symptoms between the two members of a couple were associated with interpersonal dynamics of f0 as well. There were no associations with anxiety symptoms. Thus, depressive symptoms were associated with characteristic interpersonal dynamics of vocally-encoded emotional arousal; yet, most consistent associations emerged for relationship distress, which future studies on individual psychopathology should take into account.

Fundamental frequency (F0) has been widely studied and used in the context of speaker discrimination and forensic voice comparison casework, but most previous studies focused on long-term F0 statistics. Lexical tone, the linguistically structured and dynamic aspects of F0, has received much less research attention. A main methodological issue lies on how tonal F0 should be parameterized for the best speaker discrimination performance. This paper compares the speaker discriminatory performance of three approaches with lexical tone modeling: discrete cosine transform (DCT), polynomial curve fitting, and quantitative target approximation (qTA). Results show that using parameters based on DCT and polynomials led to similarly promising performance, whereas those based on qTA generally yielded relatively poor performance. Implications modeling surface tonal F0 and the underlying articulatory processes for speaker discrimination are discussed.

A human laryngeal model, incorporating all the cartilages and the intrinsic muscles, was reconstructed based on MRI data. The vocal fold was represented as a multilayer structure with detailed inner components. The activation levels of the thyroarytenoid (TA) and cricothyroid (CT) muscles were systematically varied from zero to full activation allowing for the analysis of their interaction and influence on vocal fold dynamics and glottal flow. The finite element method was employed to calculate the vocal fold dynamics, while the one-dimensional Bernoulli equation was utilized to calculate the glottal flow. The analysis was focused on the muscle influence on the fundamental frequency (fo). We found that while CT and TA  activation increased the fo in most of the conditions, TA activation resulted in a frequency drop when it was moderately activated. We show that this frequency drop was associated with the sudden increase of the vertical motion when the vibration transited from involving the whole tissue to mainly in the cover layer. The transition of the vibration pattern was caused by the increased body-cover stiffness ratio that resulted from TA activation.

Background Thyroidectomy is a routinely performed surgical procedure used to treat benign, malignant, and some hormonal disorders of the thyroid that are not responsive to medical therapy. Voice alterations following thyroid surgery are well-documented and often attributed to recurrent laryngeal nerve dysfunction. However, subtle changes in voice quality can persist despite anatomically intact laryngeal nerves. This study aimed to quantify post-thyroidectomy voice changes in patients with intact laryngeal nerves, focusing on fundamental frequency, first formant frequency, shimmer intensity, and maximum phonation duration. Methodology This cross-sectional study was conducted at a tertiary referral center in central India and focused on post-thyroidectomy patients with normal vocal cord function. Preoperative assessments included laryngeal endoscopy and voice recording using a computer program, with evaluations repeated at one and three months post-surgery. Patients with normal laryngeal endoscopic findings underwent voice analysis and provided feedback on subjective voice changes. The PRAAT version 6.2 software was utilized for voice analysis. Results The study included 41 patients with normal laryngoscopic findings after thyroid surgery, with the majority being female (85.4%) and the average age being 42.4 years. Hemithyroidectomy was performed in 41.4% of patients and total thyroidectomy in 58.6%, with eight patients undergoing central compartment neck dissection. Except for one patient, the majority reported no subjective change in voice following surgery. Objective voice analysis showed statistically significant changes in the one-month postoperative period compared to preoperative values, including a 5.87% decrease in fundamental frequency, a 1.37% decrease in shimmer intensity, and a 6.24% decrease in first formant frequency, along with a 4.35% decrease in maximum phonatory duration. These trends persisted at the three-month postoperative period, although values approached close to preoperative levels. Results revealed statistically significant alterations in voice parameters, particularly fundamental frequency and first formant frequency, with greater values observed in total thyroidectomy patients. Shimmer intensity also exhibited slight changes. Comparison between hemithyroidectomy and total thyroidectomy groups revealed no significant differences in fundamental frequency, first formant frequency, and shimmer. However, maximum phonation duration showed a significantly greater change in the hemithyroidectomy group at both one-month and three-month postoperative intervals. Conclusions This study on post-thyroidectomy patients with normal vocal cord movement revealed significant changes in voice parameters postoperatively, with most patients reporting no subjective voice changes. The findings highlight the importance of objective voice analysis in assessing post-thyroidectomy voice outcomes.

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.

OBJECTIVE: To investigate how listeners use fundamental frequency, implied vocal tract length, and source spectral tilt to infer speaker gender.
METHODS: Sound files each containing the vowels /i, æ, ɑ, u/ interspersed by brief silences were synthesized. Each of the 210 stimuli was a combination of 10 values for fundamental frequency and 7 values for implied vocal tract length (and the associated formant frequencies) ranging from male-typical to female-typical, and 3 values for source spectral tilt approximating the voice qualities of breathy, normal, and pressed. Twenty-three listeners judged each synthesized \"speaker\" as \"female\" or \"male.\" Generalized linear mixed model analysis was used to determine the extent to which fundamental frequency, implied vocal track length, and spectral tilt influenced listener judgment.
RESULTS: Increasing fundamental frequency and decreasing implied vocal tract length resulted in increased probability of female judgment. Two interactions were identified: An increase in fundamental frequency and also a decrease in source spectral tilt (more negative) resulted in a greater increase in the probability of female judgment when the vocal tract length was relatively short.
CONCLUSIONS: The relationships among fundamental frequency, implied vocal tract length, source spectral tilt, and probability of female judgment changed across the range of normal values, suggesting that the relative contributions of fundamental frequency and implied vocal tract length to gender perception varied over the ranges studied. There was no threshold of fundamental frequency or implied vocal tract length that dramatically shifted the perception between male and female.

Global pollinator decline urgently requires effective methods to assess their trends, distribution and behaviour. Passive acoustics is a non-invasive and cost-efficient monitoring tool increasingly employed for monitoring animal communities. However, insect sounds remain highly unexplored, hindering the application of this technique for pollinators. To overcome this shortfall and support future developments, we recorded and characterized wingbeat sounds of a variety of Iberian domestic and wild bees and tested their relationship with taxonomic, morphological, behavioural and environmental traits at inter- and intra-specific levels. Using directional microphones and machine learning, we shed light on the acoustic signature of bee wingbeat sounds and their potential to be used for species identification and monitoring. Our results revealed that frequency of wingbeat sounds is negatively related with body size and environmental temperature (between-species analysis), while it is positively related with experimentally induced stress conditions (within-individual analysis). We also found a characteristic acoustic signature in the European honeybee that supported automated classification of this bee from a pool of wild bees, paving the way for passive acoustic monitoring of pollinators. Overall, these findings confirm that insect sounds during flight activity can provide insights on individual and species traits, and hence suggest novel and promising applications for this endangered animal group. This article is part of the theme issue \'Towards a toolkit for global insect biodiversity monitoring\'.

This study examines the impact of fundamental frequency on gender perception in prepubertal children in the LoKiS database - a longitudinal project collecting and analyzing recordings of approximately 60 German primary school children aged 6 to 10years. Spontaneous and content-controlled audio recordings were collected in two German primary schools. Three distinct listening experiments with over 100 listeners were conducted. In the first experiment, listeners judged the gender of the voices on a seven-point scale. The second experiment explored the relationships between perceptual attribute ratings and corresponding acoustic parameters associated with fundamental frequency. The third experiment utilized voice morphing techniques to investigate the influence of fundamental frequency on gender perception while controlling for other acoustic parameters. About one-third of the children receive unambiguous gender attributions. The perceived gender difference between children assigned female at birth (AFAB) and assigned male at birth (AMAB) increases from first to third grade. The feminine-sounding children were perceived as significantly higher-pitched and more melodious. A strong correlation between perceived pitch and measured fundamental frequency was found. While the acoustic analysis revealed only a few significant differences between AFAB and AMAB children in general, the feminine-sounding children exhibited markedly higher values than the masculine-sounding ones. Stronger differences of fundamental frequency and semitone range occur as AFAB and AMAB children get older. Linear mixed models confirm a significant influence of fundamental frequency and semitone range on gender perception. Other interacting factors include the speech material used, as well as the gender of the listener. The influence of fundamental frequency was even more pronounced when controlling for other acoustic parameters.

OBJECTIVE: In this prospective study, we aimed to investigate the difference in voice acoustic parameters between girls with idiopathic central precocious puberty (ICPP) and those who developed normally during prepuberty.
METHODS: Our study recruited 54 girls diagnosed with ICPP and randomly sampled 51 healthy prepubertal girls as the control. Tanner stages, circulating hormone levels and bone ages of the girls with ICPP and the age and body mass index (BMI) of all participants were recorded. Acoustic analyses were performed using PRAAT computer-based voice analysis software and the mean pitch (F0), jitter, shimmer, noise-to harmonic-ratio (NHR) and harmonic-to-noise ratio (HNR) values were compared in the patient and control groups.
RESULTS: The two groups did not significantly differ in age or BMI. In the evaluation of the F0 and jitter values, we were found to be lower in the control group than in the patient group. However, we did not find a statistical significance. The mean shimmer values of the patient group were significantly higher than those of the control group. In addition, a statistically significant difference was noted for the mean HNR and NHR values (P < 0.001). A moderate negative correlation was found between shimmer and hormone levels in the patient group.
CONCLUSIONS: Voice acoustic parameters one of the defining features of girls with ICPP. Voice changes in acoustic parameters could reflect hormonal changes during puberty. Clinicians should suspect ICPP when there is a change in the voice.