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.

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.

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.

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.

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.