VOCAL BIOMARKERS OF CLINICAL DEPRESSION: WORKING TOWARDS AN INTEGRATED MODEL OF DEPRESSION AND SPEECH

Speech output has long been considered a sensitive marker of a person’s mental state. It has been previously examined as a possible biomarker for diagnosis and treatment response for certain mental health conditions, including clinical depression. To date, it has been difficult to draw robust conclusions from past results due to diversity in samples, speech material, investigated parameters, and analytical methods. Within this exploratory study of speech in clinically depressed individuals, articulatory and phonatory behaviours are examined in relation to psychomotor symptom profiles and overall symptom severity. A systematic review provided context from the existing body of knowledge on the effects of depression on speech, and provided context for experimental setup within this body of work. Examinations of vowel space, monophthong, and diphthong productions as well as a multivariate acoustic analysis of other speech parameters (e.g., F0 range, perturbation measures, composite measures, etc.) are undertaken with the goal of creating a working model of the effects of depression on speech. Initial results demonstrate that overall vowel space area was not different between depressed and healthy speakers, but on closer inspection, this was due to more specific deficits seen in depressed patients along the first formant (F1) axis. Speakers with depression were more likely to produce centralised vowels along F1, as compared to F2—and this was more pronounced for low-front vowels, which are more complex given the degree of tongue-jaw coupling required for production. This pattern was seen in both monophthong and diphthong productions. Other articulatory and phonatory measures were inspected in a factor analysis as well, suggesting additional vocal biomarkers for consideration in diagnosis and treatment assessment of depression—including aperiodicity measures (e.g., higher shimmer and jitter), changes in spectral slope and tilt, and additive noise measures such as increased harmonics-to-noise ratio. Intonation was also affected by diagnostic status, but only for specific speech tasks. These results suggest that laryngeal and articulatory control is reduced by depression. Findings support the clinical utility of combining Ellgring and Scherer’s (1996) psychomotor retardation and social-emotional hypotheses to explain the effects of depression on speech, which suggest observed changes are due to a combination of cognitive, psycho-physiological and motoric mechanisms. Ultimately, depressive speech is able to be modelled along a continuum of hypo- to hyper-speech, where depressed individuals are able to assess communicative situations, assess speech requirements, and then engage in the minimum amount of motoric output necessary to convey their message. As speakers fluctuate with depressive symptoms throughout the course of their disorder, they move along the hypo-hyper-speech continuum and their speech is impacted accordingly. Recommendations for future clinical investigations of the effects of depression on speech are also presented, including suggestions for recording and reporting standards. Results contribute towards cross-disciplinary research into speech analysis between the fields of psychiatry, computer science, and speech science

Pan European Voice Conference - PEVOC 11

The Pan European VOice Conference (PEVOC) was born in 1995 and therefore in 2015 it celebrates the 20th anniversary of its establishment: an important milestone that clearly expresses the strength and interest of the scientific community for the topics of this conference. The most significant themes of PEVOC are singing pedagogy and art, but also occupational voice disorders, neurology, rehabilitation, image and video analysis. PEVOC takes place in different European cities every two years (www.pevoc.org). The PEVOC 11 conference includes a symposium of the Collegium Medicorum Theatri (www.comet collegium.com

The influence of channel and source degradations on intelligibility and physiological measurements of effort

Despite the fact that everyday listening is compromised by acoustic degradations, individuals show a remarkable ability to understand degraded speech. However, recent trends in speech perception research emphasise the cognitive load imposed by degraded speech on both normal-hearing and hearing-impaired listeners. The perception of degraded speech is often studied through channel degradations such as background noise. However, source degradations determined by talkers’ acoustic-phonetic characteristics have been studied to a lesser extent, especially in the context of listening effort models. Similarly, little attention has been given to speaking effort, i.e., effort experienced by talkers when producing speech under channel degradations. This thesis aims to provide a holistic understanding of communication effort, i.e., taking into account both listener and talker factors. Three pupillometry studies are presented. In the first study, speech was recorded for 16 Southern British English speakers and presented to normal-hearing listeners in quiet and in combination with three degradations: noise-vocoding, masking and time-compression. Results showed that acoustic-phonetic talker characteristics predicted intelligibility of degraded speech, but not listening effort, as likely indexed by pupil dilation. In the second study, older hearing-impaired listeners were presented fast time-compressed speech under simulated room acoustics. Intelligibility was kept at high levels. Results showed that both fast speech and reverberant speech were associated with higher listening effort, as suggested by pupillometry. Discrepancies between pupillometry and perceived effort ratings suggest that both methods should be employed in speech perception research to pinpoint processing effort. While findings from the first two studies support models of degraded speech perception, emphasising the relevance of source degradations, they also have methodological implications for pupillometry paradigms. In the third study, pupillometry was combined with a speech production task, aiming to establish an equivalent to listening effort for talkers: speaking effort. Normal-hearing participants were asked to read and produce speech in quiet or in the presence of different types of masking: stationary and modulated speech-shaped noise, and competing-talker masking. Results indicated that while talkers acoustically enhance their speech more under stationary masking, larger pupil dilation associated with competing-speaker masking reflected higher speaking effort. Results from all three studies are discussed in conjunction with models of degraded speech perception and production. Listening effort models are revisited to incorporate pupillometry results from speech production paradigms. Given the new approach of investigating source factors using pupillometry, methodological issues are discussed as well. The main insight provided by this thesis, i.e., the feasibility of applying pupillometry to situations involving listener and talker factors, is suggested to guide future research employing naturalistic conversations

Models and Analysis of Vocal Emissions for Biomedical Applications

The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies

The frontotemporal organization of the arcuate fasciculus and its relationship with speech perception in young and older amateur singers and non-singers

The ability to perceive speech in noise (SPiN) declines with age. Although the etiology of SPiN decline is not well understood, accumulating evidence suggests a role for the dorsal speech stream. While age-related decline within the dorsal speech stream would negatively affect SPiN performance, experience-induced neuroplastic changes within the dorsal speech stream could positively affect SPiN performance. Here, we investigated the relationship between SPiN performance and the structure of the arcuate fasciculus (AF), which forms the white matter scaffolding of the dorsal speech stream, in aging singers and non-singers. Forty-three non-singers and 41 singers aged 20 to 87 years old completed a hearing evaluation and a magnetic resonance imaging session that included High Angular Resolution Diffusion Imaging. The groups were matched for sex, age, education, handedness, cognitive level, and musical instrument experience. A subgroup of participants completed syllable discrimination in the noise task. The AF was divided into 10 segments to explore potential local specializations for SPiN. The results show that, in carefully matched groups of singers and nonsingers (a) myelin and/or axonal membrane deterioration within the bilateral frontotemporal AF segments are associated with SPiN difficulties in aging singers and non-singers; (b) the structure of the AF is different in singers and non-singers; (c) these differences are not associated with a benefit on SPiN performance for singers. This study clarifies the etiology of SPiN difficulties by supporting the hypothesis for the role of aging of the dorsal speech stream

Proceedings of the 7th international conference on disability, virtual reality and associated technologies, with ArtAbilitation (ICDVRAT 2008)

The proceedings of the conferenc

Models and analysis of vocal emissions for biomedical applications

This book of Proceedings collects the papers presented at the 3rd International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2003, held 10-12 December 2003, Firenze, Italy. The workshop is organised every two years, and aims to stimulate contacts between specialists active in research and industrial developments, in the area of voice analysis for biomedical applications. The scope of the Workshop includes all aspects of voice modelling and analysis, ranging from fundamental research to all kinds of biomedical applications and related established and advanced technologies

A Framework for Speechreading Acquisition Tools

At least 360 million people worldwide have disabling hearing loss that frequently causes difficulties in day-to-day conversations. Hearing aids often fail to offer enough benefits and have low adoption rates. However, people with hearing loss find that speechreading can improve their understanding during conversation. Speechreading (often called lipreading) refers to using visual information about the movements of a speaker's lips, teeth, and tongue to help understand what they are saying. Speechreading is commonly used by people with all severities of hearing loss to understand speech, and people with typical hearing also speechread (albeit subconsciously) to help them understand others. However, speechreading is a skill that takes considerable practice to acquire. Publicly-funded speechreading classes are sometimes provided, and have been shown to improve speechreading acquisition. However, classes are only provided in a handful of countries around the world and students can only practice effectively when attending class. Existing tools have been designed to help improve speechreading acquisition, but are often not effective because they have not been designed within the context of contemporary speechreading lessons or practice. To address this, in this thesis I present a novel speechreading acquisition framework that can be used to design Speechreading Acquisition Tools (SATs) - a new type of technology to improve speechreading acquisition.Comment: PhD Thesis, supervised by Dr David R. Flatl

Behavioural and neural insights into the recognition and motivational salience of familiar voice identities

The majority of voices encountered in everyday life belong to people we know, such as close friends, relatives, or romantic partners. However, research to date has overlooked this type of familiarity when investigating voice identity perception. This thesis aimed to address this gap in the literature, through a detailed investigation of voice perception across different types of familiarity: personally familiar voices, famous voices, and lab-trained voices. The experimental chapters of the thesis cover two broad research topics: 1) Measuring the recognition and representation of personally familiar voice identities in comparison with labtrained identities, and 2) Investigating motivation and reward in relation to hearing personally valued voices compared with unfamiliar voice identities. In the first of these, an exploration of the extent of human voice recognition capabilities was undertaken using personally familiar voices of romantic partners. The perceptual benefits of personal familiarity for voice and speech perception were examined, as well as an investigation into how voice identity representations are formed through exposure to new voice identities. Evidence for highly robust voice representations for personally familiar voices was found in the face of perceptual challenges, which greatly exceeded those found for lab-trained voices of varying levels of familiarity. Conclusions are drawn about the relevance of the amount and type of exposure on speaker recognition, the expertise we have with certain voices, and the framing of familiarity as a continuum rather than a binary categorisation. The second topic utilised voices of famous singers and their “super-fans” as listeners to probe reward and motivational responses to hearing these valued voices, using behavioural and neuroimaging experiments. Listeners were found to work harder, as evidenced by faster reaction times, to hear their musical idol compared to less valued voices in an effort-based decision-making task, and the neural correlates of these effects are reported and examined