Voice Discrimination Research Articles

Self-other voice discrimination task: A potential neuropsychological tool for clinical assessment of self-related deficits

BackgroundDeficits in self are commonly described through different neuro-pathologies, based on clinical evaluations and experimental paradigms. However, currently available approaches lack appropriate clinical validation, making objective evaluation and discrimination of self-related deficits challenging. MethodsWe applied a statistical standardized method to assess the clinical discriminatory capacity of a Self-Other Voice Discrimination (SOVD) task. This task, validated experimentally as a marker for self-related deficits, was administered to 17 patients eligible for neurosurgery due to focal hemispheric brain tumors or epileptic lesions. ResultsThe clinical discriminatory capacity of the SOVD task was evident in three patients who exhibited impairments for self-voice perception that could not be predicted by other neuropsychological deficits. Impairments in other-voice perception were linked to inhibitory neuropsychological deficits, suggesting a potential association with executive deficits in voice recognition. ConclusionsThis exploratory study highlights the clinical discriminatory potential of the SOVD task and suggests that it could complement the standard neuropsychological assessment, paving the way for enhanced diagnoses and tailored treatments for self-related deficits.

Voice disorder discrimination using vowel acoustic measures in female speakers.

Sustained vowels are important vocal tasks that have been investigated in discriminating voice disorders using acoustic analysis. To date, no study has combined vowel acoustic measures only that evaluate major aspects of the pathological voice signals in voice disorder discrimination. To investigate the value of vowel acoustic measures that quantify glottal noise, signal stability, signal periodicity, spectral slope and overall voice quality in discriminating female speakers with and without voice disorders. Sustained vowel /ɑ/ samples were extracted from 133 voice-disordered female patients and 97 non-voice disordered female speakers and were signal typed prior to analysis. Praat software was used to measure harmonics-to-noise ratio (HNR), glottal-to-noise excitation ratio (GNE), the standard deviation of fundamental frequency (F0SD) and cepstral peak prominence (CPPp); and the Analysis of Dysphonia in Speech and Voice (ADSV) program was used to measure CPPadsv, low/high spectral ratio (LH) and the cepstral/spectral index of dysphonia (CSID). Outcome measures included sensitivity, specificity, and discrimination accuracy. As individual acoustic measures, only spectral-based measures showed good (CPPadsv) and acceptable (CSID) discrimination results. The HNR, GNE and CPPp measures had acceptable sensitivity but poor or non-acceptable specificity and discrimination accuracy. Logistic regression models with all Praat measures (F0SD, HNR, GNE, CPPp) plus ADSV measures (CPPadsv, LH or CSID) provided excellent sensitivity, good-to-excellent specificity and excellent discrimination accuracy. ROC analysis for all individual measures showed that CPPadsv, CSID, CPPp, GNE and F0SD had the highest area under the curve (AUC) values. A combination of acoustic measures that evaluate the major aspects of vocal dysfunction resulted in good to excellent voice discrimination outcomes. Individual acoustic measures had lower discrimination ability than combined measures. The findings implied that acoustic measures extracted from a prolonged vowel were useful in voice disorder discrimination. What is already known on this subject Acoustic measures hold great value in discriminating voice disorders from normal voices. However, no study has evaluated discrimination values of a combination of sustained vowel acoustic measures that quantify additive noise, signal stability, signal periodicity, spectral slope and overall voice quality in single-gender cohorts. Previous studies have not used signal typing (the classification of the acoustic signals) for time-based measures, impacting the reliability of discrimination. What this study adds to the existing knowledge This study was the first to implement signal typing to include sustained vowel samples of Types 1 and 2 signals for discrimination statistics. We showed that a combination of vocal acoustic measures using time- and spectral-based extraction from the sustained /ɑ/ vowel evaluating additive noise, signal stability, signal periodicity, spectral slope and overall voice quality resulted in good to excellent sensitivity, specificity and discrimination accuracy. As individual measures, traditional time-based measures such as HNR had rather limited discrimination values whilst spectral-based measures provided higher discrimination values. Measures that are sensitive to signal types have low discrimination ability. What are the potential or actual clinical implications of this work? The sustained vowel /ɑ/ is a relevant, universal vocal task for clinical application using acoustic measures to discriminate female speakers with and without voice disorders if signal typing is implemented. Clinical voice assessment using vowels may not be effective if relying solely on time-based measurements. Spectral-based measures perform better in voice disorder discrimination given their insensitivity to signal types. The most effective voice disorder discrimination could only be obtained using a combination of acoustic measures that quantify major phenomena in the signals of disordered voices. Using measures extracted from both programs, Praat and ADSV, is useful given that specific settings in a program may impact on discrimination accuracy.

Prelingually Deaf Children With Cochlear Implants Show Better Perception of Voice Cues and Speech in Competing Speech Than Postlingually Deaf Adults With Cochlear Implants.

Postlingually deaf adults with cochlear implants (CIs) have difficulties with perceiving differences in speakers' voice characteristics and benefit little from voice differences for the perception of speech in competing speech. However, not much is known yet about the perception and use of voice characteristics in prelingually deaf implanted children with CIs. Unlike CI adults, most CI children became deaf during the acquisition of language. Extensive neuroplastic changes during childhood could make CI children better at using the available acoustic cues than CI adults, or the lack of exposure to a normal acoustic speech signal could make it more difficult for them to learn which acoustic cues they should attend to. This study aimed to examine to what degree CI children can perceive voice cues and benefit from voice differences for perceiving speech in competing speech, comparing their abilities to those of normal-hearing (NH) children and CI adults. CI children's voice cue discrimination (experiment 1), voice gender categorization (experiment 2), and benefit from target-masker voice differences for perceiving speech in competing speech (experiment 3) were examined in three experiments. The main focus was on the perception of mean fundamental frequency (F0) and vocal-tract length (VTL), the primary acoustic cues related to speakers' anatomy and perceived voice characteristics, such as voice gender. CI children's F0 and VTL discrimination thresholds indicated lower sensitivity to differences compared with their NH-age-equivalent peers, but their mean discrimination thresholds of 5.92 semitones (st) for F0 and 4.10 st for VTL indicated higher sensitivity than postlingually deaf CI adults with mean thresholds of 9.19 st for F0 and 7.19 st for VTL. Furthermore, CI children's perceptual weighting of F0 and VTL cues for voice gender categorization closely resembled that of their NH-age-equivalent peers, in contrast with CI adults. Finally, CI children had more difficulties in perceiving speech in competing speech than their NH-age-equivalent peers, but they performed better than CI adults. Unlike CI adults, CI children showed a benefit from target-masker voice differences in F0 and VTL, similar to NH children. Although CI children's F0 and VTL voice discrimination scores were overall lower than those of NH children, their weighting of F0 and VTL cues for voice gender categorization and their benefit from target-masker differences in F0 and VTL resembled that of NH children. Together, these results suggest that prelingually deaf implanted CI children can effectively utilize spectrotemporally degraded F0 and VTL cues for voice and speech perception, generally outperforming postlingually deaf CI adults in comparable tasks. These findings underscore the presence of F0 and VTL cues in the CI signal to a certain degree and suggest other factors contributing to the perception challenges faced by CI adults.

Perception of speaker identity for bilingual voices

Voice is often described as an “auditory face”; it provides important information concerning speaker identity (e.g., age, height, sex). The acoustic properties related to voice can also vary substantially within a speaker based on one’s emotional, social, and linguistic states. Recent work suggests that biological components have the greatest impact in the acoustic variability found in voice, followed by language-specific factors and speaking style [Lee & Kreiman, J. Acoust. Soc. Am. 153, A295 (2023)]. The effects of such within- vs. between-speaker acoustic variability on the perception of speaker identity, however, have not been explored. The present study therefore examines the perception of speaker identity in bilingual voices. The prediction is that acoustic variability will also affect speaker identity perception: voices will be discriminated best for between-speaker samples, while within-speaker variability will not affect perception of speaker to the same extent. To test this prediction, listeners participated in a voice discrimination task using bilingual voice data produced by Korean heritage speakers across different languages (Korean, English) and speech styles (read, extemporaneous). The data will be analyzed to measure the effects of speaker, language, and speech style on voice discrimination. The results will be reported in relevance to the relationship between bilingualism and speech style on voice quality and speaker identity.

The Impact of Trained Conditions on the Generalization of Learning Gains Following Voice Discrimination Training.

Auditory training can lead to notable enhancements in specific tasks, but whether these improvements generalize to untrained tasks like speech-in-noise (SIN) recognition remains uncertain. This study examined how training conditions affect generalization. Fifty-five young adults were divided into "Trained-in-Quiet" (n = 15), "Trained-in-Noise" (n = 20), and "Control" (n = 20) groups. Participants completed two sessions. The first session involved an assessment of SIN recognition and voice discrimination (VD) with word or sentence stimuli, employing combined fundamental frequency (F0) + formant frequencies voice cues. Subsequently, only the trained groups proceeded to an interleaved training phase, encompassing six VD blocks with sentence stimuli, utilizing either F0-only or formant-only cues. The second session replicated the interleaved training for the trained groups, followed by a second assessment conducted by all three groups, identical to the first session. Results showed significant improvements in the trained task regardless of training conditions. However, VD training with a single cue did not enhance VD with both cues beyond control group improvements, suggesting limited generalization. Notably, the Trained-in-Noise group exhibited the most significant SIN recognition improvements posttraining, implying generalization across tasks that share similar acoustic conditions. Overall, findings suggest training conditions impact generalization by influencing processing levels associated with the trained task. Training in noisy conditions may prompt higher auditory and/or cognitive processing than training in quiet, potentially extending skills to tasks involving challenging listening conditions, such as SIN recognition. These insights hold significant theoretical and clinical implications, potentially advancing the development of effective auditory training protocols.

Unveiling Self-Related Deficits in Neurosurgical Patients: Insights from the Self-Other Voice Discrimination Task as a Neuropsychological Tool

Unveiling Self-Related Deficits in Neurosurgical Patients: Insights from the Self-Other Voice Discrimination Task as a Neuropsychological Tool

Discrimination of familiar and unfamiliar human voices is independent of prolonged human-animal interaction in domestic chicks

Different animal species, both domestic and wild, can discriminate between various human cues, such as voices, and adjust their behavior based on whether they are familiar or unfamiliar with these cues. To investigate whether this ability extends to a domesticated species not specifically bred for human interaction and whether it can manifest at an early age, even under commercial-like conditions with limited human interaction, we conducted human vocal discrimination tests on domestic chicks at two ages (25 and 67 days old). Our findings showed that chicks could discriminate between familiar and unfamiliar voices at both ages, exhibiting increased vigilance when a known sentence was spoken by an unfamiliar voice compared to a familiar voice. We also found that chicks were more vigilant after a familiar voice delivered an unknown sentence, compared to an unfamiliar voice delivered a known sentence. This suggests a violation of expectation when animals are confronted with mixed familiar/unfamiliar heterospecific signals. Our findings support that neither specific selection for interaction with humans, nor an extended history of exposure to humans, is a prerequisite for animals to discriminate heterospecific cues, such as human voices.

Voice Discrimination in Quiet and in Background Noise by Simulated and Real Cochlear Implant Users.

Cochlear implant (CI) users demonstrate poor voice discrimination (VD) in quiet conditions based on the speaker's fundamental frequency (fo) and formant frequencies (i.e., vocal-tract length [VTL]). Our purpose was to examine the effect of background noise at levels that allow good speech recognition thresholds (SRTs) on VD via acoustic CI simulations and CI hearing. Forty-eight normal-hearing (NH) listeners who listened via noise-excited (n = 20) or sinewave (n = 28) vocoders and 10 prelingually deaf CI users (i.e., whose hearing loss began before language acquisition) participated in the study. First, the signal-to-noise ratio (SNR) that yields 70.7% correct SRT was assessed using an adaptive sentence-in-noise test. Next, the CI simulation listeners performed 12 adaptive VDs: six in quiet conditions, two with each cue (fo, VTL, fo + VTL), and six amid speech-shaped noise. The CI participants performed six VDs: one with each cue, in quiet and amid noise. SNR at VD testing was 5 dB higher than the individual's SRT in noise (SRTn +5 dB). Results showed the following: (a) Better VD was achieved via the noise-excited than the sinewave vocoder, with the noise-excited vocoder better mimicking CI VD; (b) background noise had a limited negative effect on VD, only for the CI simulation listeners; and (c) there was a significant association between SNR at testing and VTL VD only for the CI simulation listeners. For NH listeners who listen to CI simulations, noise that allows good SRT can nevertheless impede VD, probably because VD depends more on bottom-up sensory processing. Conversely, for prelingually deaf CI users, noise that allows good SRT hardly affects VD, suggesting that they rely strongly on bottom-up processing for both VD and speech recognition.

The Effect of Noise on the Utilization of Fundamental Frequency and Formants for Voice Discrimination in Children and Adults

The ability to discriminate between talkers based on their fundamental (F0) and formant frequencies can facilitate speech comprehension in multi-talker environments. To date, voice discrimination (VD) of children and adults has only been tested in quiet conditions. This study examines the effect of speech-shaped noise on the use of F0 only, formants only, and the combined F0 + formant cues for VD. A total of 24 adults (18–35 years) and 16 children (7–10 years) underwent VD threshold assessments in quiet and noisy environments with the tested cues. Thresholds were obtained using a three-interval, three-alternative, two-down, one-up adaptive procedure. The results demonstrated that noise negatively impacted the utilization of formants for VD. Consequently, F0 became the lead cue for VD for the adults in noisy environments, whereas the formants were the more accessible cue for VD in quiet environments. For children, however, both cues were poorly utilized in noisy environments. The finding that robust cues such as formants are not readily available for VD in noisy conditions has significant clinical implications. Specifically, the reliance on F0 in noisy environments highlights the difficulties that children encounter in multi-talker environments due to their poor F0 discrimination and emphasizes the importance of maintaining F0 cues in speech-processing strategies tailored for hearing devices.

Evaluation of perception of music, environmental sounds, and speech in right versus left cerebral stroke patients

BackgroundStroke is a leading cause of disability and about a third of stroke survivors have aphasia. Stroke also may affect all levels of the auditory pathway and lead to hearing reception and/or perception deficits for different sound types.Aim of the workThe aim of the work is to evaluate the perception of music, environmental sounds, and speech in post-stroke patients in order to determine if there is a difference in the basic auditory perceptual abilities in right versus left cerebral stroke.Subjects and methodsA group of 30 healthy adults and a group of 30 right and left cerebral stroke patients with an age range from 35 to 75 years old were included. The participants were evaluated using a 10-item designed questionnaire for auditory abilities and a test of auditory perceptual/recognition skills. The questionnaire addressed some of the basic auditory skills of attention, discrimination, and recognition of environmental sounds and human voice. The test consisted of non-verbal and verbal domains. The non-verbal domain involved music recognition, discrimination, perception, performance, and environmental sound recognition tasks. While the verbal domain included; recognition of the sound related to speech stimuli and syllable/word recognition tasks.ResultsBetter significant scores in right versus left stroke patients regarding questionnaire results for attention to sound sources either near or fear (p value < 0.001) and discriminating prosodic intonation of statement or interrogation (p value = < 0.001). There was no significant difference between the right cerebral stroke group and the left cerebral stroke group regarding the score of music perception and music performance tasks of the non-verbal domain of the auditory perceptual/recognition skills assessment. Better significant scores were found in the right cerebral stroke patients than the left cerebral stroke patients regarding the scores of both the non-verbal and verbal domains of the auditory perceptual/recognition skills assessment.ConclusionStroke of both right and left cerebral hemispheres has a specific negative effect on some aspects of perception of music, environmental sounds, and speech that need to be addressed in both evaluation protocols and rehabilitation programs.

Grey wolves (Canis lupus) discriminate between familiar and unfamiliar human voices.

The ability to discriminate between different individuals based on identity cues, which is important to support the social behaviour of many animal species, has mostly been investigated in conspecific contexts. A rare example of individual heterospecific discrimination is found in domestic dogs, who are capable of recognising their owners' voices. Here, we test whether grey wolves, the nearest wild relative of dogs, also have the ability to distinguish familiar human voices, which would indicate that dogs' ability is not a consequence of domestication. Using the habituation-dishabituation paradigm, we presented captive wolves with playback recordings of their keepers' and strangers' voices producing either familiar or unfamiliar phrases. The duration of their responsewas significantly longer when presented with keepers' voices than with strangers' voices, demonstrating that wolves discriminated between familiar and unfamiliar speakers. This suggests that dogs' ability to discriminate between human voices was probably present in their common ancestor and may support the idea that this is a general ability of vertebrates to recognise heterospecific individuals. Our study also provides further evidence for familiar voice discrimination in a wild animal in captivity, indicating that this ability may be widespread across vertebrate species.

The Right Temporal Lobe and the Enhancement of Voice Recognition in Congenitally Blind Subjects

Experimental investigations and clinical observations have shown that not only faces but also voices are predominantly processed by the right hemisphere. Moreover, right brain-damaged patients show more difficulties with voice than with face recognition. Finally, healthy subjects undergoing right temporal anodal stimulation improve their voice but not their face recognition. This asymmetry between face and voice recognition in the right hemisphere could be due to the greater complexity of voice processing. To further investigate this issue, we tested voice and name recognition in twelve congenitally blind people. The results showed a complete overlap between the components of voice recognition impaired in patients with right temporal damage and those improved in congenitally blind people. Congenitally blind subjects, indeed, scored significantly better than control sighted individuals in voice discrimination and produced fewer false alarms on familiarity judgement of famous voices, corresponding to tests selectively impaired in patients with right temporal lesions. We suggest that task difficulty is a factor that impacts on the degree of its lateralization.

The underlying mechanisms for voice discrimination across the life span

Speech understanding in noisy conditions changes across the life span. One strategy that assists listening in multi-talker noise is to track the voice of the relevant speaker, based on his/her fundamental frequency (F0) and formant frequencies (reflecting vocal tract length). Thus, age-related differences in voice discrimination (VD) may explain some of the difficulties that children or older-adults have in speech-in-noise perception. The present experiments aimed to assess VD from childhood to old age and explore the underlying mechanisms for VD across ages. Four experiments assessed difference limens (DLs) for VD, using an oddball paradigm with two-down one-up adaptive procedure in quiet conditions (Two experiments, including 41 children, 36 young-adults, and 15 older-adults), amid speech-shaped noise (16 children, 24 young-adults, and 12 older-adults) and following different testing methods (32 children, and 31 young-adults). Working memory, attention, and speed of processing were also assessed. The poorest VD was shown for the youngest children and the older-adults, with better cognitive abilities and/or improved acoustic accessibility/resolution advancing VD for these groups. children and older-adults may engage more top-down (cognitive) and bottom-up (periphery) resources for VD compared to young-adults, which may partly explain their difficulties in understanding speech in multi-talker environments.

Bone conduction facilitates self-other voice discrimination.

One's own voice is one of the most important and most frequently heard voices. Although it is the sound we associate most with ourselves, it is perceived as strange when played back in a recording. One of the main reasons is the lack of bone conduction that is inevitably present when hearing one's own voice while speaking. The resulting discrepancy between experimental and natural self-voice stimuli has significantly impeded self-voice research, rendering it one of the least investigated aspects of self-consciousness. Accordingly, factors that contribute to self-voice perception remain largely unknown. In a series of three studies, we rectified this ecological discrepancy by augmenting experimental self-voice stimuli with bone-conducted vibrotactile stimulation that is present during natural self-voice perception. Combining voice morphing with psychophysics, we demonstrate that specifically self-other but not familiar-other voice discrimination improved for stimuli presented using bone as compared with air conduction. Furthermore, our data outline independent contributions of familiarity and acoustic processing to separating the own from another's voice: although vocal differences increased general voice discrimination, self-voices were more confused with familiar than unfamiliar voices, regardless of their acoustic similarity. Collectively, our findings show that concomitant vibrotactile stimulation improves auditory self-identification, thereby portraying self-voice as a fundamentally multi-modal construct.

Vowel convergence does not affect auditory speaker discriminability in humans and machine in a case study on Swiss German dialects

In this study, we examined whether the convergence in interlocutors’ vowel acoustics leads to decreasing discriminability between interlocutors’ voices. Ten pairs of Grison and Zürich German speakers produced lexical items before and after dialogue interactions with evidence of vowel convergence in post-dialogue productions. In Experiment 1, native and non-native Swiss German listeners discriminated pairs of speakers whose speech was obtained pre- and post-dialogue. Results showed that listeners’ sensitivity (A’) was higher for native than non-native listeners, but comparable for pre- and post-dialogue recordings. The observed negative correlation between voice discrimination and the acoustic distance in formant space was mainly driven by a single speaker pair. In Experiment 2, the speaker recognition performance of an i-vector-based software was compared in pre- and post-dialogue speech. Results revealed no difference in the system performance between the two conditions. The findings suggest that vowel convergence does not compromise voice discriminability under the given experimental conditions.

Developmental Changes in the Perception of Vocal Loudness and Voice Quality in 3- to 6-Year-Old Children.

The study's primary aim was to investigate developmental changes in the perception of vocal loudness and voice quality in children 3-6 years of age. A second aim was to evaluate a testing procedure-the intermodal preferential looking paradigm (IPLP)-for the study of voice perception in young children. Participants were categorized in two age groups: 3- to 4-year-olds and 5- to 6-year-olds. Children were tested remotely via a Zoom appointment and completed two perceptual tasks: (a) voice discrimination and (b) voice identification. Each task consisted of two tests: a vocal loudness test and a voice quality test. Children in the 5- to 6-year-old group were significantly more accurate than children in the 3- to 4-year-old group in discriminating and identifying differences between voices for both loudness and voice quality. The IPLP, used in the identification task, was found to successfully detect differences between the age groups for overall accuracy and for most of the sublevels of vocal loudness and voice quality. Results suggest that children's ability to discriminate and identify differences in vocal loudness and voice quality improves with age. Findings also support the use of the IPLP as a useful tool to study voice perception in young children.

Distinct functional levels of human voice processing in the auditory cortex.

Voice signaling is integral to human communication, and a cortical voice area seemed to support the discrimination of voices from other auditory objects. This large cortical voice area in the auditory cortex (AC) was suggested to process voices selectively, but its functional differentiation remained elusive. We used neuroimaging while humans processed voices and nonvoice sounds, and artificial sounds that mimicked certain voice sound features. First and surprisingly, specific auditory cortical voice processing beyond basic acoustic sound analyses is only supported by a very small portion of the originally described voice area in higher-order AC located centrally in superior Te3. Second, besides this core voice processing area, large parts of the remaining voice area in low- and higher-order AC only accessorily process voices and might primarily pick up nonspecific psychoacoustic differences between voices and nonvoices. Third, a specific subfield of low-order AC seems to specifically decode acoustic sound features that are relevant but not exclusive for voice detection. Taken together, the previously defined voice area might have been overestimated since cortical support for human voice processing seems rather restricted. Cortical voice processing also seems to be functionally more diverse and embedded in broader functional principles of the human auditory system.

Difficulties Experienced by Older Listeners in Utilizing Voice Cues for Speaker Discrimination.

Human listeners are assumed to apply different strategies to improve speech recognition in background noise. Young listeners with normal hearing (NH), e.g., have been shown to follow the voice of a particular speaker based on the fundamental (F0) and formant frequencies, which are both influenced by the gender, age, and size of the speaker. However, the auditory and cognitive processes that underlie the extraction and discrimination of these voice cues across speakers may be subject to age-related decline. The present study aimed to examine the utilization of F0 and formant cues for voice discrimination (VD) in older adults with hearing expected for their age. Difference limens (DLs) for VD were estimated in 15 healthy older adults (65–78 years old) and 35 young adults (18–35 years old) using only F0 cues, only formant frequency cues, and a combination of F0 + formant frequencies. A three-alternative forced-choice paradigm with an adaptive-tracking threshold-seeking procedure was used. Wechsler backward digit span test was used as a measure of auditory working memory. Trail Making Test (TMT) was used to provide cognitive information reflecting a combined effect of processing speed, mental flexibility, and executive control abilities. The results showed that (a) the mean VD thresholds of the older adults were poorer than those of the young adults for all voice cues, although larger variability was observed among the older listeners; (b) both age groups found the formant cues more beneficial for VD, compared to the F0 cues, and the combined (F0 + formant) cues resulted in better thresholds, compared to each cue separately; (c) significant associations were found for the older adults in the combined F0 + formant condition between VD and TMT scores, and between VD and hearing sensitivity, supporting the notion that a decline with age in both top-down and bottom-up mechanisms may hamper the ability of older adults to discriminate between voices. The present findings suggest that older listeners may have difficulty following the voice of a specific speaker and thus implementing doing so as a strategy for listening amid noise. This may contribute to understanding their reported difficulty listening in adverse conditions.

Breathing affects self-other voice discrimination in a bodily state associated with somatic passivity.

A growing number of studies have focused on identifying cognitive processes that are modulated by interoceptive signals, particularly in relation to the respiratory or cardiac cycle. Considering the fundamental role of interoception in bodily self‐consciousness, we here investigated whether interoceptive signals also impact self‐voice perception. We applied an interactive, robotic paradigm associated with somatic passivity (a bodily state characterized by illusory misattribution of self‐generated touches to someone else) to investigate whether somatic passivity impacts self‐voice perception as a function of concurrent interoceptive signals. Participants' breathing and heartbeat signals were recorded while they performed two self‐voice tasks (self‐other voice discrimination and loudness perception) and while simultaneously experiencing two robotic conditions (somatic passivity condition; control condition). Our data reveal that respiration, but not cardiac activity, affects self‐voice perception: participants were better at discriminating self‐voice from another person’s voice during the inspiration phase of the respiration cycle. Moreover, breathing effects were prominent in participants experiencing somatic passivity and a different task with the same stimuli (i.e., judging the loudness and not identity of the voices) was unaffected by breathing. Combining interoception and voice perception with self‐monitoring framework, these data extend findings on breathing‐dependent changes in perception and cognition to self‐related processing.

Auditory perceptual assessment of voices: Examining perceptual ratings as a function of voice experience

Understanding voice usage is vital to our understanding of human interaction. What is known about the auditory perceptual evaluation of voices comes mainly from studies of voice professionals, who evaluate operatic/lyrical singing in specific contexts. This is surprising as recordings of singing voices from different musical styles are an omnipresent phenomenon, evoking reactions in listeners with various levels of expertise. Understanding how untrained listeners perceive and describe voices will open up new research possibilities and enhance vocal communication between listeners. Here three studies with a mixed-methods approach aimed at: (1) evaluating the ability of untrained listeners to describe voices, and (2) determining what auditory features were most salient in participants’ discrimination of voices. In an interview (N = 20) and a questionnaire study (N = 48), free voice descriptions by untrained listeners of 23 singing voices primarily from popular music were compared with terms used by voice professionals, revealing that participants were able to describe voices using vocal characteristics from essential categories indicating sound quality, pitch changes, articulation, and variability in expression. Nine items were derived and used in an online survey for the evaluation of six voices by trained and untrained listeners in a German (N = 216) and an English (N = 50) sample, revealing that neither language nor expertise affected the assessment of the singers. A discriminant analysis showed that roughness and tension were important features for voice discrimination. The measurement of vocal expression created in the current study will be informative for studying voice perception and evaluation more generally.