Simone Graetzer

Effects of speech style, room acoustics, and vocal fatigue on vocal effort

Vocal effort is a physiological measure that accounts for changes in voice production as vocal loading increases. It has been quantified in terms of sound pressure level (SPL). This study investigates how vocal effort is affected by speaking style, room acoustics, and short-term vocal fatigue. Twenty subjects were recorded while reading a text at normal and loud volumes in anechoic, semi-reverberant, and reverberant rooms in the presence of classroom babble noise. The acoustics in each environment were modified by creating a strong first reflection in the talker position. After each task, the subjects answered questions addressing their perception of the vocal effort, comfort, control, and clarity of their own voice. Variation in SPL for each subject was measured per task. It was found that SPL and self-reported effort increased in the loud style and decreased when the reflective panels were present and when reverberation time increased. Self-reported comfort and control decreased in the loud style, while self-reported clarity increased when panels were present. The lowest magnitude of vocal fatigue was experienced in the semi-reverberant room. The results indicate that early reflections may be used to reduce vocal effort without modifying reverberation time.

Effects of voice style, noise level, and acoustic feedback on objective and subjective voice evaluations

Speakers adjust their vocal effort when communicating in different room acoustic and noise conditions and when instructed to speak at different volumes. The present paper reports on the effects of voice style, noise level, and acoustic feedback on vocal effort, evaluated as sound pressure level, and self-reported vocal fatigue, comfort, and control. Speakers increased their level in the presence of babble and when instructed to talk in a loud style, and lowered it when acoustic feedback was increased and when talking in a soft style. Self-reported responses indicated a preference for the normal style without babble noise.

Evaluation of the starting point of the lombard effect

Speakers increase their vocal effort when their communication is disturbed by noise. This adaptation is termed the Lombard effect. The aim of the present study was to determine whether this effect has a starting point. Hence, the effects of noise at levels between 20 and 65 dB(A) on vocal effort (quantified by sound pressure level) and on both perceived noise disturbance and perceived vocal discomfort were evaluated. Results indicate that there is a Lombard effect change-point at a background noise level (Ln) of 43.3 dB(A). This change-point is anticipated by noise disturbance, and is followed by a high magnitude of vocal discomfort.

Effect of Training and Level of External Auditory Feedback on the Singing Voice: Volume and Quality

BACKGROUND Previous research suggests that classically trained professional singers rely not only on external auditory feedback but also on proprioceptive feedback associated with internal voice sensitivities. OBJECTIVES The Lombard effect and the relationship between sound pressure level (SPL) and external auditory feedback were evaluated for professional and nonprofessional singers. Additionally, the relationship between voice quality, evaluated in terms of singing power ratio (SPR), and external auditory feedback, level of accompaniment, voice register, and singer gender was analyzed. METHODS The subjects were 10 amateur or beginner singers and 10 classically trained professional or semiprofessional singers (10 men and 10 women). Subjects sang an excerpt from the Star-Spangled Banner with three different levels of the accompaniment, 70, 80, and 90 dBA and with three different levels of external auditory feedback. SPL and SPR were analyzed. RESULTS The Lombard effect was stronger for nonprofessional singers than professional singers. Higher levels of external auditory feedback were associated with a reduction in SPL. As predicted, the mean SPR was higher for professional singers than nonprofessional singers. Better voice quality was detected in the presence of higher levels of external auditory feedback. CONCLUSIONS With an increase in training, the singers reliance on external auditory feedback decreases.

Gender differences and speech accommodation in occupational settings

Nearly one quarter of the U.S. workforce depends on a healthy, versatile voice as a tool for their profession. These are individuals who, lose voice quality and/or vocal endurance, would not be able to perform their job effectively. These occupational voice users include professionals such as teachers, counselors, emergency dispatchers, air traffic controllers, performers, and telephone workers. Women tend to have a disproportionate incidence of reported voice problems compared to men. They also make up the majority of several of these high voice-use occupations (e.g., public school teachers, call center workers). This presentation will provide an overview of our current understanding of gender discrepancy in vocal health issues as well as a discussion of recent results identifying underlying causes, which may contribute to their heightened risk. Such results include compensatory adjustments women use in different communication environments, speech accommodation to stress, and the relationship between voc...

Videos influence behavior change measures for voice and speech in individuals with Parkinson's disease

The majority of individuals with Parkinsons disease (PD) experience voice and speech difficulties at some point over the course of the disease. Voice therapy has been found to help improve voice and speech in individuals with PD, but the majority of these individuals do not enroll in voice therapy. The purpose of this study was to determine whether watching short videos about voice symptoms and treatment in Parkinsons disease influences readiness to change, stages of change, and self-efficacy in individuals with PD. Eight individuals with PD participated in the study. Fifteen videos were chosen, three representing each of the five stages of change. We chose videos from YouTube that represented variety in speakers, content, and genre. We found that readiness to change significantly increased after watching videos, suggesting that watching videos helped these individuals move closer to actively improving their voice and speech. In addition, five of the eight participants showed forward movement in stages of change. Finally, self-efficacy demonstrated a positive trend following video watching. Overall, our results demonstrate that watching videos available on the internet can influence individuals with Parkinsons disease in changing vocal behavior. Implications for future wireless health applications are described.

Locus equations and coarticulation in three Australian languages

Locus equations were applied to F2 data for bilabial, alveolar, retroflex, palatal, and velar plosives in three Australian languages. In addition, F2 variance at the vowel-consonant boundary, and, by extension, consonantal coarticulatory sensitivity, was measured. The locus equation slopes revealed that there were place-dependent differences in the magnitude of vowel-to-consonant coarticulation. As in previous studies, the non-coronal (bilabial and velar) consonants tended to be associated with the highest slopes, palatal consonants tended to be associated with the lowest slopes, and alveolar and retroflex slopes tended to be low to intermediate. Similarly, F2 variance measurements indicated that non-coronals displayed greater coarticulatory sensitivity to adjacent vowels than did coronals. Thus, both the magnitude of vowel-to-consonant coarticulation and the magnitude of consonantal coarticulatory sensitivity were seen to vary inversely with the magnitude of consonantal articulatory constraint. The findings indicated that, unlike results reported previously for European languages such as English, anticipatory vowel-to-consonant coarticulation tends to exceed carryover coarticulation in these Australian languages. Accordingly, on the F2 variance measure, consonants tended to be more sensitive to the coarticulatory effects of the following vowel. Prosodic prominence of vowels was a less significant factor in general, although certain language-specific patterns were observed.

Effect of Training and Level of External Auditory Feedback on the Singing Voice: Pitch Inaccuracy

BACKGROUND One of the most important aspects of singing is the control of fundamental frequency. OBJECTIVES The effects on pitch inaccuracy, defined as the distance in cents in equally tempered tuning between the reference note and the sung note, of the following conditions were evaluated: (1) level of external feedback, (2) tempo (slow or fast), (3) articulation (legato or staccato), (4) tessitura (low, medium, or high), and (5) semi-phrase direction (ascending or descending). METHODS The subjects were 10 nonprofessional singers and 10 classically trained professional or semi-professional singers (10 men and 10 women). Subjects sang one octave and a fifth arpeggi with three different levels of external auditory feedback, two tempi, and two articulations (legato or staccato). RESULTS It was observed that inaccuracy was greatest in the descending semi-phrase arpeggi produced at a fast tempo and with a staccato articulation, especially for nonprofessional singers. The magnitude of inaccuracy was also relatively large in the high tessitura relative to the low and the medium tessitura for such singers. Contrary to predictions, when external auditory feedback was strongly attenuated by the hearing protectors, nonprofessional singers showed greater pitch accuracy than in the other external feedback conditions. This finding indicates the importance of internal auditory feedback in pitch control. CONCLUSIONS With an increase in training, the singers pitch inaccuracy decreases.

Hyperarticulation in short intonational phrases in three Australian languages

In Lindbloms Hyper- and Hypo-articulation (H & H) theory, speech varies between clear and less clear depending on the communicative context. Hyperarticulation is known to reflect prosodic boundary information and prosodic prominence or focus. The realisation of hyperarticulation appears to differ between languages. In this study of three Australian languages, it is asked whether, in pre-boundary position in short prosodic phrases, vowel lengthening tends to co-occur with acoustic evidence of hyperarticulation. Further, it is asked whether hyperarticulation is stronger in the pre-boundary syllable than in the post-boundary one. It is demonstrated that pre-boundary lengthening in short intonational phrases in Australian languages tends to co-occur with an increase in vowel peripherality.

Speech accommodation to room acoustics: Reverberation time and clarity

Vocal effort is a physiological entity that accounts for changes in voice production as vocal loading increases, which can be quantified in terms of sound pressure level (SPL). This study investigates how vocal effort is affected by speaking style, room acoustics, and short-term vocal fatigue. Twenty subjects were recorded while reading a text at normal and loud volumes in anechoic, semi-reverberant, and reverberant rooms in the presence of babble noise. The acoustics in each environment were modified by increasing the strength of the early reflections in the talker position. The subjects answered questions addressing their perception of vocal effort, comfort, control, and the clarity of their own voice. SPL variation for each subject was measured per task. It was found that SPL and self-reported effort increased in the loud style and decreased when the reflective panels were present and when reverberation time increased. In contrast, self-reported comfort and control decreased in the loud style, while se...