This thesis examines the phonetic, phonological, and social aspects of pre-aspiration in English spoken in Aberystwyth, mid Wales. Pre-aspiration refers to a period of voiceless (primarily) glottal friction occurring in the sequences of sonorants and phonetically voiceless obstruents (e.g. in mat [mahts] or mass [mahs]). Chapter 1 summarises the objectives of this thesis and where the thesis is positioned with respect to our current knowledge of the phenomenon and the relevant theoretical issues. Chapter 2 introduces the data used to address these objectives. Pre-aspiration is usually considered as consisting of a voiced glottal component, or breathiness, and a voiceless glottal component, or voiceless pre-aspiration, and these are treated as a single unit in a number of analyses (Helgason 2003; Helgason & Ringen 2008; Karlsson & Svantesson 2011; Morris 2010; Ringen & van Dommelen 2013; Stevens & Hajek 2004b, 2004c; Stevens 2010, 2011). Chapter 3 shows that this is not adequate because distinguishing the two enables us to discover patterns that would remain obscured otherwise – such as breathiness being a possible precursor to pre-aspiration. This is demonstrated through the segmental and prosodic conditioning of pre-aspiration and breathiness. Chapter 4 shows that although pre-aspiration is not an obligatory feature of Aberystwyth English (in the sense that it would occur in 100% of time where it can), it nevertheless forms two clear categories sensitive to phonological rather than phonetic vowel height. However, phonological vowel height on its own cannot explain these two categories and interacts with a number of other conditioning factors. Whilst Chapter 3 investigates the relationship between pre-aspiration and breathiness, Chapter 5 looks into that of pre-aspiration and glottalisation and demonstrates that the two can occur in the same environment, which enlightens the debates related to the historical connections between pre-aspiration and glottalisation in particular (e.g. Kortland 1988). It furthermore reveals that although it is not known why they are co-occurring for some speakers and mutually exclusive or allophonic for others, their relationship is conditioned prosodically and not segmentally. Chapter 6 illustrates that pre-aspiration is an acoustic correlate of the fortis-lenis contrast in plosives in production at least equally well as breathiness, voicing, release duration, or the duration of the preceding vowel, and better than voiceless closure duration, glottalisation, or f0 before or after the plosive in question in the word-medial (cotter [khɒhtsə] ~ codder [khɒdə]) and the word-final positions (cot ~ cod). It is therefore at least as important as the other four correlates. Chapter 7 finds that pre-aspiration also exhibits social conditioning. Females pre-aspirate more frequently than males, which is often found in pre-aspiration studies, but this difference disappears as the age decreases. Furthermore, the frequency of breathiness, and the duration of pre-aspiration and breathiness are not conditioned by gender. However, all four variables are affected by age. Pre-aspiration thus seems to be undergoing an advancing sound change according to Labov’s Principle II (2001: 292) and breathiness seems to be its precursor. Chapter 8 summarises the results and outlines questions for further research.

The voice is a fundamental method of communication and as such, helps in our efforts to define our identity. Projection of the appropriate voice is crucially important to transgender individuals in transition for acceptance as their identified gender. This study attempts to identify and examine the relationship between acoustic measurements of voice quality and the perception of speaker gender from audio recordings, including the male-to-female transgender voice, based on several acoustic properties that have been identified by previous studies. Recordings of female, male and transgender voices were acoustically analyzed for properties relating to differences in voice quality between men and women. Listeners then identified the gender of the recorded voices, with the intention of evaluating which voices are perceived as either male or female along with a corresponding rating of masculinity or femininity. What acoustic measurements of voice quality cue listeners to gender and do they correlate with gender perception?

Title:EFFECTS OF THE PROMINENCE OF FIRST HARMONIC ON THE PERCEPTION OF BREATHINESS AND VOWEL IDENTITY Authors: Emily Lin, Samuel Sloane,and Donal Sinex Background: Human communication relies on adequate speech intelligibility to enable the comprehension of verbal messages. Dysphonia (i.e., aberrant voice) may not only result in distraction during communication but also interfere with speech intelligibility leading to a communication barrier. One voice quality commonly found in dysphonia is breathiness, which is related to the presence of excessive airflow during phonation due to incomplete glottal closure. Breathiness has been associated with the prominence of the first harmonic (H1) in the acoustic analysis of voice. Objectives: This study aimed to determine whether excessiveness in the first harmonic (H1) dominance, which has been associated with breathy voice, may result in the perception of breathiness and compromise vowel intelligibility. Methods: Participants included 10 female and 10 male normal-hearing adults, aged between 19 to 40 years. Participant’s tasks included a “breathiness rating” and a “vowel identification” task. For the “breathiness rating” task, a direct magnitude method was employed for the participant to rate a 500-ms long vowel (/i/ and /a/) segmented from sustained vowel phonation. For the “vowel identification” task, the vowel stimuli were segmented out from running speech (“Rainbow passage”) and the participants were asked to listen to one vowel stimulus (/i/, /a/, or /o/; duration: 60 ms) at a time and indicate which vowel (i.e., /i/, /e/, /a/, /o/, or /u/) they perceived the stimulus to be. The vowel stimuli included processed and unprocessed voice recordings of individuals with and without voice disorders. Voices showing the lowest, median, and highest amplitude differences between the first two harmonics (H1-H2) were chosen from a voice database for female and male voices respectively. The 18 selected vowel signals (3 vowels X 3 H1-H2 levels X 2 speaker genders) were processed through 12 signal manipulation conditions. The 12 signal conditions involved increasing or decreasing the H1 amplitude of the original signals in six 2-dB interval steps in both directions. Results: For the “breathiness rating” task, the five-way (3 vowels X 2 speaker genders X 3 H1-H2 levels X 13 signal conditions X 2 listener genders) Mixed Model Analysis of variance (ANOVA) conducted on the breathiness scores for normal speakers and voice patients separately showed significant findings for various main and interaction effects, such as a significant speaker gender by signal condition by vowel interaction effect on the perception of breathiness [F(12, 96) = 1.95, p = 0.038] for normal voice. An increase of H1-H2 through signal manipulation led to an increase of perceived breathiness only when performed on the vowel /i/ produced by female normal speakers. As for the “vowel identification” task, a relationship between H1-H2 increment and vowel intelligibility was found but the relationship was affected by vowel type, speaker gender, and H1-H2 level. With all vowel types, speaker genders, and H1-H2 levels combined, a significant signal condition effect on the number of incorrect vowel identification was found (2 = 188.585, df = 10, p < 0.001). Generally, it appeared that an increase of H1-H2 would worsen the identification of /i/ but enhance that of /o/. Conclusion: The relationship between H1 dominance and perceived breathiness was non-linear. Factors found to disrupt the linear relationship included speaker gender, vowel type, and the extent of H1 dominance. In addition, there was evidence that acoustic manipulation of the H1 amplitude would affect vowel intelligibility and the relationship between vowel intelligibility and H1-H2 values also vary by speaker genders and vowel types.

Aim The aim of this study was to determine how deterioration of voice quality, such as breathiness, may impact on the intelligibility of speech. Method Acoustic analysis was conducted on sustained vowel phonation (/i/ and /a/) and sentences produced by voice disordered speakers. Measures included: frequency and amplitude of the first two formants (F1, F2), singing power ratio (SPR), the amplitude difference between the first two harmonics (H1-H2), voice onset time (VOT), and energy ratio between consonant and vowel (CV energy ratio). A series of two-way (glottal closure by vowel) mixed design between and within-subjects Analysis of Variances conducted on these acoustic measures showed a significant glottal closure (complete and incomplete) or glottal closure by vowel interaction effect on the F2 frequency, H1-H2 amplitude difference, and singing power ratio. Based on findings in literature that reported a dominant first harmonic as a useful predictor of breathiness, the measure of H1-H2 amplitude difference was selected as a factor for investigation of the impact of voice quality on the perception of vowel intelligibility and clarity. Fixed-length vowel segments at five levels of H1-H2 amplitude difference were presented to 10 male and 10 female inexperienced listeners between the ages of 19 and 34 years. Results It was expected that the tokens with a dominant first harmonic, indicative of a more breathy voice, would be associated with a lower rate of correct vowel identification and of being perceived as “clearer”. Although no linear relationship between breathiness and intelligibility was revealed, results indicated the presence of thresholds of intelligibility for particular vowels whereby once a level of breathiness was reached intelligibility would decline. Conclusion The finding of a change of the perceptual ratings as a function of the H1-H2 amplitude difference, identified in previous studies as a measure of breathiness, revealed thresholds of intelligibility for particular vowels below which breathiness would be tolerated with little impact on intelligibility but beyond which intelligibility ratings suffered markedly.

Poor breath management is problematic for singing. Voice students and singing teachers typically attribute breath management issues to abdominal-diaphragmatic breathing technique. The present study seeks to determine whether glottal insufficiency may also contribute to singer’s breath management problems. Studies have revealed a relationship between incomplete vocal fold closure and inefficiency in the speaking voice. However, the effect of incomplete vocal fold closure on vocal efficiency in singers has yet to be determined. Since the larynx cannot be observed without the assistance of clinical instrumentation, not readily available in the voice studio, issues at the glottal level may be underappreciated as a contributor to poor breath management in the singer. Two groups of voice students identified with and without breath management problems underwent aerodynamic and acoustic voice assessment as well as videostroboscopy of the vocal folds to quantify the prevalence of incomplete vocal fold closure. These assessments revealed four groups: (1) those with glottic insufficiency and no perceived breathiness; (2) those with glottic sufficiency and perceived breathiness; (3) those with glottic insufficiency and perceived breathiness; and, (4) those with glottic sufficiency and no perceived breathiness. Results suggest that previously undiscovered glottal insufficiency is common, though the correlation with identified breath management problems was not statistically significant. Acoustic and aerodynamic measures including noise-to-harmonics ratio, maximum phonation time, airflow rate, subglottal pressure and laryngeal airway resistance were most sensitive to glottic insufficiency.

Rating scales are commonly used to study voice quality. The purpose of this study was to examine inter-rater reliability/agreement of graduate student clinicians with differing levels of experience in rating voice perception. The Consensus Auditory Perception Evaluation of Voice (CAPE-V) was used to asses 1.) overall severity, 2.) roughness, 3.) breathiness, 4.) strain, 5.) pitch and 6.) loudness from a sample of pediatric voices. Twenty-four graduate clinicians who had completed a graduate level course in voice disorders participated in the study. Twelve of the participants were randomly selected to complete a perceptual training course prior to the evaluation session. Voice samples included 10 disordered and 2 normal voices from a population of children age 3-10 years old. The 12 voice samples were randomly repeated 3 times. Results of analysis of variance indicated that the groups significantly differed in their severity rating of the perceptual indices, suggesting that training affected the participants' judgment of severity. Additionally, variability was reduced as a function of training. Pearson product-moment correlation coefficient's revealed a moderate to strong relationship for all of the perceptual indices suggesting that regardless of training participants have an implicit understanding of normal versus disordered voice samples.

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