Maintaining Professional Performance Viability With Age.

Some classically trained singers demonstrate great performance longevity. These singers continue to produce a professionally viable voice that belies their age. This study was designed to assess selected acoustic characteristics of 10 currently performing classical singers from 2 recordings; one early, and one recent. The mean age at the early and recent recording was 39 and 64, respectively, with a mean of 25 years between recordings. Vibrato rate, extent, and consistency were calculated. The singers also completed a questionnaire to determine their strategies to maintain high-quality vocal production. From the early to recent recordings, overall, the participants demonstrated the expected decrease in vibrato rate, with little change in vibrato extent and consistency. The reported strategies included very individualized approaches regarding vocalizing regimens and maintenance of pitch accuracy. All agreed on the importance of increased self-awareness, openness to feedback, and dedicated preparation for upcoming performance. Our findings indicate that some singers are indeed ageless, but this attribute is not inherent; rather it requires diligent and devoted practice.

Steam and/or Semi-occluded Vocal Tract Exercise as Morning Vocal Warm-up Strategy.

OBJECTIVE: This study was designed to evaluate the effectiveness of either steam, semi-occluded vocal tract (SOVT) exercises, or a combination of both as a speaking voice warm-up strategy to be used at the start of the day. METHODS/DESIGN: This prospective study assessed the impact of three different vocal warm-up conditions on phonatory threshold pressure (PTP). The three conditions were: (1) Steam - breathing steam for 3 minutes; (2) SOVT exercise - blowing bubbles through a straw into a cup of water while phonating /u/ for 3 minutes; and (3) Steam + SOVT - both conditions 1 and 2. Participants were 12 females with a mean age of 24. They were assessed on three different mornings, with one condition being tested each morning. Condition order and combination order were counterbalanced. Each morning prior to arriving, participants were asked to be up for about an hour, with no shower, no hot drinks or food, minimal voice-use, and no exercise. PTP was measured prior to each condition and immediately after. Participants also qualitatively described the experience of each condition and provided their subjective impression of how their voice felt after each condition. RESULTS: There were 36 data points, reflecting change in PTP from before to after each condition. Results reflected high variability within each individual and condition. Due to this variability, means and standard deviations for each separate condition are meaningless, requiring deeper investigation into trends in the data. The investigators eliminated all data points where the sound pressure level (SPL) in the pre-experimental measure exceeded 67 dB; this was interpreted as the participant not performing the PTP task as softly as possible. First, data were examined within each participant, excluding all data from any participant who exceeded 67 dB SPL in any of the three pre-experimental measures. Of the seven participants remaining, steam was the best condition for one, SOVT was the best for three, and Steam + SOVT was the best for three. Of these, only two people experienced an improvement in PTP of greater than or equal to 0.5 cm H 2 O, both under the SOVT condition. Of the same seven participants, steam was the worst condition for three, SOVT was the worst for one, and Steam + SOVT was the worst for two. The three participants for whom steam was the worst reported strongly disliking the condition. Only three people experienced a worsening of PTP greater than or equal to 0.5 cm H 2 O: one in the SOVT condition; and two in the Steam + SOVT. It is typically expected that increases or decreases in PTP and SPL will be systematically related. Since the goal of a warm-up is to increase phonatory efficiency, and improve the viscosity of the vocal folds, a reduction in PTP after any condition was interpreted favorably. For the 9 data points across all conditions where PTP and SPL both decreased, there was a mean decrease in PTP of 0.34 cm H2O (SD = 0.28 cm H2O ). Mean decrease in SPL was 2.00 dB (SD = 0.88 dB). This indicates that individuals were able to decrease PTP and SPL as expected after a warm-up strategy. Finally, a trend appeared in six data points, where despite an increase in SPL, PTP decreased, potentially indicating improvement in vocal efficiency. Of these data points the mean decrease in PTP was 0.36 cm H2O ( SD = 0.17 cm H2O ), with a mean increase in SPL of 1.70 dB (SD = 1.21 dB). Of these six data points, indicating increased efficiency, three were with steam, two with Steam + SOVT, and one with SOVT. CONCLUSION: This study revealed that these strategies are not universally successful, and clinicians should recommend them only after assessing their effectiveness for their client. Clinicians need to be custom tailoring these exercises to their client's goals and proclivities. Another consideration is the importance of teaching proper SOVT technique, so it is done correctly without added tension. Even blowing bubbles into a cup of water with phonation can be done poorly, in some cases yielding counterproductive results. Another interesting trend suggests that the inclusion of steam in vocal warm-up may increase vocal efficiency. Future studies should explore how time of day and vocal condition impact each strategy's effectiveness, and which strategy may be most appropriate for different desired outcomes, such as vocal warmup versus vocal rescue.

Aerobic Exercise as a Warm-up for Singing: Acoustic Impacts.

OBJECTIVES: In a previous work, it was found that a 30-minute aerobic workout significantly increased singers' sound pressure level and airflow during voicing, suggesting a shift to flow phonation. This companion study was designed to assess the impact of the same workout on pitch accuracy, vibrato rate, extent and regularity, and the singing power ratio. STUDY DESIGN: This study is a cohort experimental study. METHODS: Twenty-two students in an academic vocal performance program participated. They performed an aerobic workout for 30 minutes. Before and after the workout, they sang the first seven notes of the "Star-Spangled Banner" on /pa/, producing seven /pa/s on the last note. The students then sang an ascending and descending scale to the ninth on "ah." The following measures were obtained from the "Star-Spangled Banner": pitch accuracy calculated on the seventh note ("by"); and vibrato rate, regularity, and extent, calculated on the most sustained sixth note ("see"). For the scale, the following measures were calculated from each note: pitch accuracy; vibrato rate, regularity, and extent; and the singing power ratio. RESULTS: There were no significant differences from pre- to postworkout across any measures. CONCLUSIONS: It appears that an aerobic workout positively impacts the respiratory driving force for voice production but does little for phonation. Critical for performance is the fine tuning and balancing across the respiratory, laryngeal, and resonance systems. It appears that this can only be achieved with vocalization exercises, facilitating coordination within and across the physiological systems involved in the complex art of bel canto.

Speech changes induced by deep brain stimulation of the subthalamic nucleus in Parkinson disease: involvement of the dentatorubrothalamic tract.

OBJECTIVE Patients with Parkinson disease (PD) who undergo subthalamic nucleus (STN) deep brain stimulation (DBS) often develop a deterioration in speech performance, but there is no clear consensus on the specific effects seen or the mechanism involved and little description of the impact of DBS on conversational speech. Furthermore, there has been no fiber tract connectivity analysis to identify the structures potentially modulated by DBS to cause such deficits. The main objective of this study was to quantify spontaneous speech performance and identify potential involvement of the dentatorubrothalamic tract (DRTt) in patients who underwent STN DBS, because this tract has been implicated in speech deterioration. METHODS Spontaneous speech samples were obtained with STN DBS in both on and off modes in 35 patients with PD and assessed across multiple domains. Diffusion tensor imaging tractography seeded from the therapeutic DBS contacts was performed to identify the fiber tracts involved and, specifically, the DRTt. The position of active electrode contacts was assessed relative to that of the STN. RESULTS Fifteen patients with akinetic-rigid (AR) PD and 20 with tremor-dominant (TD) PD subtypes were identified. In the AR-PD subgroup of patients, in whom there was DRTt involvement, 71% demonstrated much better overall speech and largely improved or unchanged fluency in the DBS-off condition. In patients with TD PD with DRTt involvement, 50% demonstrated better overall speech in the off condition, and equivocal results regarding improved or worsened fluency were found. When there was minimal DRTt involvement, 75% of patients with AR PD had better overall speech in the DBS-on condition and better or minimal fluency changes. Similarly, 83% of patients with TD PD with minimal DRTt involvement had better or minimal overall speech and fluency changes in the on condition. More medially placed left electrode contacts were associated with more DRTt involvement in 77% of patients (10 of 13). CONCLUSIONS To the authors' knowledge, this is the first study to have investigated a specific fiber tract involved in STN DBS in different subtypes of PD relative to its impact on spontaneous speech. At optimal therapeutic programming of STN DBS, overall spontaneous speech and fluency were affected more negatively in patients with AR PD than in those with TD PD when there was DRTt involvement. After fiber tract analysis and modeling, it was found that medially positioned left electrode contacts more often involved fibers of the DRTt. If possible, avoidance of the DRTt by using active electrode contacts that are positioned less medially, specifically in patients with AR PD, might result in less speech deterioration.

Aerobic Exercise as a Warm-Up for Singing: Aerodynamic Changes.

OBJECTIVES: This study was designed to determine the impact of aerobic exercise on vocal warm-up. STUDY DESIGN: This is a cohort experimental study. METHODS: Sixteen graduate and six undergraduate students in an academic vocal performance program participated. They completed a 30-minute treadmill workout in their target aerobic heart range. Aerodynamic data during singing were acquired before and after the treadmill workout. In full voice, participants sang the first seven notes of the Star Spangled Banner on "pah," repeating the seventh note seven times, at 1.5 syllables/s after an inhalation. The key was determined by voice type, with the target note within the range of passaggio for men, and in head voice for women. RESULTS: Paired t tests were performed on the data from 17 singers who maintained or increased sound pressure level (SPL) after exercise. Significant pre- to post-exercise increases were found for mean SPL and mean airflow during voicing, although increased estimated subglottal pressure approached significance. These measures were essentially unchanged in individuals who decreased SPL after exercise. There was no significant difference in vocal efficiency after the aerobic exercise, primarily due to large standard deviations within the pre- and post-exercise conditions. CONCLUSIONS: Most participants demonstrated favorable aerodynamic changes during singing after aerobic exercise. It is possible that in certain situations, a general aerobic warm-up could set the stage for a less-demanding vocal-specific warm-up, especially for a high voice performing early in the morning.

Effects of Bel Canto Training on Acoustic and Aerodynamic Characteristics of the Singing Voice.

OBJECTIVES: This study was designed to assess the impact of 2 years of operatic training on acoustic and aerodynamic characteristics of the singing voice. STUDY DESIGN: This is a longitudinal study. METHODS: Participants were 21 graduate students and 16 undergraduate students. They completed a variety of tasks, including laryngeal videostroboscopy, audio recording of pitch range, and singing of syllable trains at full voice in chest, passaggio, and head registers. Inspiration, intraoral pressure, airflow, and sound pressure level (SPL) were captured during the syllable productions. RESULTS: Both graduate and undergraduate students significantly increased semitone range and SPL. The contributions to increased SPL were typically increased inspiration, increased airflow, and reduced laryngeal resistance, although there were individual differences. Two graduate students increased SPL without increased airflow and likely used supraglottal strategies to do so. CONCLUSIONS: Students demonstrated improvements in both acoustic and aerodynamic components of singing. Increasing SPL primarily through respiratory drive is a healthy strategy and results from intensive training.

Vocal Assessment Before, After, and the Day After Opera Performance.

OBJECTIVE: To explore aerodynamic, acoustic, and laryngeal changes surrounding opera performance. STUDY DESIGN: Prospective preperformance, postperformance, and day after performance. METHODS: The laryngeal and vocal function of five male and five female classically trained singers was assessed immediately before, immediately after, and 1 day after an actual operatic performance. Phonatory threshold pressure was obtained. In addition, during a full-voice singing task, aerodynamic and acoustic measures included estimated subglottal pressure, airflow during voicing, laryngeal resistance, and sound pressure level (SPL). Expert listeners in the audience judged performers' voice quality at the beginning and the end of the performance. Laryngeal visualization was performed immediately before performance and the day after performance. RESULTS: Laryngeal stroboscopy revealed allergy symptoms with no change in vocal fold edges for all men. Women were less impacted by allergies. For all singers, perceptual judgments of expert listeners in the audience corresponded well with laryngeal findings. The men whose voices were perceived to be balanced and strong across the performance demonstrated increased airflow and reduced laryngeal resistance after performance. The two women who did not sing in church the morning after the performance demonstrated increased airflow and reduced laryngeal resistance. The two men who did sing in church the morning after the performance demonstrated noticeably reduced SPL and increased laryngeal resistance the day after performance. CONCLUSIONS: It appears most useful to describe the complexity of vocal performance with a variety of acoustic, aerodynamic, and perceptual measures. The findings further suggest that vocal rest the day after performance may facilitate recovery.

Brain-computer interfaces increase whole-brain signal to noise.

Brain-computer interfaces (BCIs) can convert mental states into signals to drive real-world devices, but it is not known if a given covert task is the same when performed with and without BCI-based control. Using a BCI likely involves additional cognitive processes, such as multitasking, attention, and conflict monitoring. In addition, it is challenging to measure the quality of covert task performance. We used whole-brain classifier-based real-time functional MRI to address these issues, because the method provides both classifier-based maps to examine the neural requirements of BCI and classification accuracy to quantify the quality of task performance. Subjects performed a covert counting task at fast and slow rates to control a visual interface. Compared with the same task when viewing but not controlling the interface, we observed that being in control of a BCI improved task classification of fast and slow counting states. Additional BCI control increased subjects' whole-brain signal-to-noise ratio compared with the absence of control. The neural pattern for control consisted of a positive network comprised of dorsal parietal and frontal regions and the anterior insula of the right hemisphere as well as an expansive negative network of regions. These findings suggest that real-time functional MRI can serve as a platform for exploring information processing and frontoparietal and insula network-based regulation of whole-brain task signal-to-noise ratio.

Singers' phonation threshold pressure and ratings of self-perceived effort on vocal tasks.

OBJECTIVES/HYPOTHESIS: This study was designed to determine if singers' self-ratings of vocal effort could predict phonation threshold pressure (PTP). It was hypothesized that effort ratings on the more complex task of singing "Happy Birthday" would best predict PTP. STUDY DESIGN: A multiple regression analysis was performed with PTP as the predicted variable and self-ratings on four phonatory tasks as the predictor variables. METHODS: Participants were 48 undergraduate and graduate students majoring in vocal performance. They produced /pi/ syllable trains as softly as possible for the measurement of PTP. They then rated their self-perceived vocal effort while softly producing the following: (1) sustained "ah" (comfortable, midrange pitch); (2) "ah" glide (chest to head voice); (3) Staccato "ah" in head voice (not falsetto); and (4) Happy Birthday in head voice (not falsetto). RESULTS: No ratings of vocal effort predicted PTP. The lack of correlation between PTP and ratings of Happy Birthday remained when separately evaluating graduate versus undergraduate students or males versus females. Informal evaluation of repeated ratings over time suggested the potential for effective self-monitoring. CONCLUSIONS: Students' ratings of self-perceived vocal effort were poor predictors of PTP. This may be because of the use of "effortless" imagery during singing instruction or consistent positive feedback regarding vocal performance. It is possible that self-rating could become an effective tool to predict vocal health if task elicitation instructions were more precise, and the student and voice teacher worked collaboratively to improve self-evaluation.

Voice analysis during bad news discussion in oncology: reduced pitch, decreased speaking rate, and nonverbal communication of empathy.

PURPOSE: This study was designed to determine if differences exist in the speaking rate and pitch of healthcare providers when discussing bad news versus neutral topics, and to assess listeners' ability to perceive voice differences in the absence of speech content. METHODS: Participants were oncology healthcare providers seeing patients with cancer of unknown primary. The encounters were audio recorded; the information communicated by the oncologist to the patient was identified as neutral or bad news. At least 30 seconds of both bad news and neutral utterances were analyzed; provider voice pitch and speaking rate were measured. The same utterances were subjected to low pass filtering that maintained pitch contours and speaking rate, but eliminated acoustic energy associated with consonants making the samples unintelligible, but with unchanged intonation. Twenty-seven listeners (graduate students in a voice disorders class) listened to the samples and rated them on three features: caring, sympathetic, and competent. RESULTS: All but one provider reduced speaking rate, the majority also reduced pitch in the bad news condition. Listeners perceived a significant difference between the nonverbal characteristics of the providers' voice when performing the two tasks and rated speech produced with the reduced rate and lower pitch as more caring and sympathetic. CONCLUSIONS: These results suggest that simultaneous assessment of verbal content and multiparameter prosodic analysis of speech is necessary for a more thorough understanding of the expression and perception of empathy. This information has the potential to contribute to the enhancement of communication training design and of oncologists' communication effectiveness.

An exploration of listener variability in intelligibility judgments.

PURPOSE: This study was designed to assess potential contributors to listener variability in judgments of intelligibility. METHOD: A total of 228 unfamiliar everyday listeners judged speech samples from 3 individuals with dysarthria. Samples were the single-word phonetic contrast test, the Sentence Intelligibility Test, an unpredictable sentence intelligibility test, and conversational speech. RESULTS: Across speakers, significant variability was found for all samples except the phonetic contrast test. Across tasks, significant variability was found for all speakers. There were no significant differences in age, gender, or education between the highest and lowest scoring listeners on the phonetic contrast test. CONCLUSIONS: These findings suggest that seemingly objective intelligibility tests are subject to a number of factors that affect scores.

Neurofeedback of two motor functions using supervised learning-based real-time functional magnetic resonance imaging.

This study examines the effects of neurofeedback provided by support vector machine (SVM) classification-based real-time functional magnetic resonance imaging (rt-fMRI) during two types of motor tasks. This approach also enables the examination of the neural regions associated with predicting mental states in different domains of motor control, which is critical to further our understanding of normal and impaired function. Healthy volunteers (n = 13) performed both a simple button tapping task, and a covert rate-of-speech counting task. The average prediction accuracy was approximately 95% for the button tapping task and 86% for the speech task. However, subsequent offline analysis revealed that classification of the initial runs was significantly lower - 75% (p<0.001) for button and 72% (p<0.005) for speech. To explore this effect, a group analysis was performed using the spatial maps derived from the SVM models, which showed significant differences between the two fMRI runs. One possible explanation for the difference in spatial patterns and the asymmetry in the prediction accuracies is that when subjects are actively engaged in the task (i.e. when they are trying to control a computer interface), they are generating stronger BOLD responses in terms of both intensity and spatial extent.

The effect of specific versus combined warm-up strategies on the voice.

Although actors and singers typically warm-up the voice before performing, little is known about the effects of vocal warm-up on the voice. This study was designed to determine the relative effectiveness of specific versus combined warm-up strategies on the voice by group comparison. Twenty participants, 10 male and 10 female actors, completed two warm-up protocols, at least 1 week apart, in a counter-balanced order. Measures of phonation threshold pressure (PTP), jitter, noise-to-harmonics-ratio (NHR), and self-perceived vocal effort were obtained. For the males, there was no significant difference in PTP difference values between vocal warm-up only (specific) and vocal plus aerobic warm-up (combined) conditions. For the females, however, a significant difference was found, with a greater reduction in PTP in the combined warm-up condition. A significant difference was also found in male jitter percent values, with significantly lower values in the specific condition than in the combined condition. There were no significant differences in the remaining comparisons. Females appeared to respond more to the vocal warm-up when it had an aerobic exercise component. It is possible that the males' greater level of physical fitness impacted this finding.

Pitch discrimination and pitch matching abilities of adults who sing inaccurately.

Past research regarding singing ability has provided evidence that both supports and refutes a relationship between pitch discrimination ability and pitch production ability. Researchers have suggested that these skills improve with age. Despite this suggestion, most investigators studying singing ability have included only children as participants. Additionally, although many researchers have studied accurate singers, few have directly studied persons who do not sing accurately. We designed this study to examine the relationship between pitch discrimination ability and pitch production ability in inaccurate adult singers. Fifteen adults, aged 18 to 40 years, that met specific criteria qualified as inaccurate singers. Each participated in two tasks, a pitch discrimination task and a pitch production task. We used the Multi-Dimensional Voice Profile-Advanced (Kay Elemetrics Corporation, Lincoln Park, NJ) to determine the frequency of each participant's vocal productions during the pitch production task. We also used a Pearson product moment correlation to analyze the relationship between pitch discrimination and pitch production accuracy within a semitone of the target frequency. No meaningful relationship was found, and results were not statistically significant. However, the inaccurate singers in this study could be classified into two separate categories, those who discriminated pitches accurately, but produced pitches inaccurately, and those who discriminated pitches inaccurately and produced pitches inaccurately. These findings may be of great importance to music educators and impact the focus of instruction when teaching an inaccurate singer to sing more accurately.

The vocal health of auctioneers.

A questionnaire designed to assess vocal demands and vocal health was completed by 438 randomly selected auctioneers. Over 96% reported using amplification to auction the majority of the time. A greater proportion of individuals who auctioned in environments with poor air quality visited a physician for a voice problem than individuals who auctioned in environments with clean air. Significant contributors to vocal quality changes and vocal fatigue were frequency of auctioning, as well as auctioning in noise. In addition, the duration of auctioning without a break significantly contributed to vocal fatigue. Vocal hygiene recommendations are provided based on these findings.

The effect of pacing strategies on the variability of speech movement sequences in dysarthria.

There are many potential sources of variability in speech production, particularly in individuals with dysarthria. The degree and time course of stabilization of the speech production system during recovery from a neurological insult is not constant across individuals. Another source of variability in speech production is speaking rate. Although individuals with no neurological impairments typically show increased variability at reduced speaking rates, this phenomenon has not been explored extensively in individuals with dysarthria. Because rate control strategies are commonly used in dysarthria treatment, it is of clinical importance to know if individuals with dysarthria produce less variable speech with rate reduction. Six individuals with mild dysarthria, 6 with moderate-to-severe dysarthria, and 6 matched normal controls repeated an utterance in four speaking rate conditions: habitual, fast, breaks between words, and stretched. Data were analyzed using the spatiotemporal index (STI), a composite measure of spatial and temporal variability across token repetitions. The normal controls consistently demonstrated the least variability, regardless of rate condition. Both groups with dysarthria were the least variable in the stretched condition and the most variable in the fast condition. The STI values of the group with moderate-to-severe dysarthria were significantly different from both the individuals with mild dysarthria and the normal controls. There were no significant differences between the group with mild dysarthria and the normal controls. In general, slowing the speaking rate in individuals with dysarthria reduces spatiotemporal variability; however, the effect of reduced spatiotemporal variability on intelligibility requires further investigation.

The effect of botulinum toxin A on the vocal symptoms of spastic dysarthria: a case study.

The vocal symptoms of spastic dysarthria and spasmodic dysphonia have many similar features. Botulinum toxin has been used effectively to treat spasmodic dysphonia. This study was designed to determine what vocal changes occur in an individual with spastic dysarthria following Botulinum toxin A injection into the thyroarytenoid muscles. Measures were obtained preinjection and three times postinjection. Acoustic and aerodynamic results were comparable to those reported for individuals with spasmodic dysphonia. The most marked change was increased DC airflow. Despite persistent breathiness, the participant reported great satisfaction with the result, particularly because of her more appropriate loudness. In addition, everyday listeners perceived significantly less listener burden and more relaxed and pleasant vocal quality postinjection.