Vocal Dosimetry: A Graduate Level Voice Pedagogy Course Experience
2013; Routledge; Volume: 69; Issue: 5 Linguagem: Inglês
ISSN
2769-4046
AutoresChristopher S. Gaskill, Jennifer G. Cowgill, Sara R. Tinter,
Tópico(s)Voice and Speech Disorders
ResumoINTRODUCTIONGRADUATE VOCAL PERFORMANCE MAJORS preparing for careers as professional singers are often preparing to be voice teachers as well. There are increasing demands placed on singers in performance programs to perform in ensembles, stage performances, singing studio courses, and opera workshops. Many also sing professionally to some degree during graduate school (such as in a local church choir). They must commit many hours to personal practice, and many also teach voice either individually or in an undergraduate class voice elective. These are heavy demands, and this does not even account for any social or vocational speaking voice use. If vocalists, teachers, and voice therapists are to be able to understand and predict the effects of heavy doses on the human mechanism, it is important to evaluate these demands, and quantify them in some way.Voice researchers have begun to think of the demands placed on the voice in terms of several measurements of vocal over any particular time interval, which can include accumulated phonation time as the folds stop and start vibration during singing and speaking tasks and the percentage of time spent phonating over a particular clock time interval.1 Two special dose measurements, cycle dose and distance dose, have also been defined as the total number of cycles of vibration of the folds in any time period, and as the actual distance traveled by the folds in their back and forth oscillation to and from the midline of the larynx.2 Distance dose considers both time, frequency of vibration (pitch), and intensity (loudness) of the voice. All of these dose measurements can be readily made on a singer by using a piece of equipment called a dosimeter, and several versions are now commercially available.A dosimeter is a small portable device that consists of a small contact microphone attached to a battery operated digital recording device. The contact microphone is attached to the skin of the neck directly below the thyroid prominence with adhesive, and the dosimeter device is usually carried in a pouch belted around the waist. The commercially available dosimeter used in this study was developed for clinical and research applications, and is called the Ambulatory Phonation Monitor (APM, KayPENTAX, Lincoln Park, NJ). Once the device is activated, the contact microphone records all vibration of the folds for the duration of the period the device is worn. Most dosimeters can record continuously for twelve hours or more, depending on the memory buffer and battery life. Data for a particular monitoring period are then retrieved from the device for analysis using accompanying computer software.Vocal dosimetry data include total elapsed phonation time, which can be reported as either accumulated phonation time, or as a percentage of the total time the device was worn (percent phonation time). The software will provide summary data for the entire monitoring period, but can also provide data for any time window of interest (for example, to compare phonation data from a choral rehearsal to solo practice time or to time spent talking with friends). In addition to time data, the dosimeter also provides fundamental frequency (F^sub 0^) or pitch data as well as intensity or loudness data. As with the phonation time data, an average value (or range of values) for frequency and intensity can be obtained for the entire elapsed monitoring time or for any time window of interest.The APM dosimeter also calculates cycle dose and distance dose, as mentioned above, and their derivation has been described fully elsewhere.3 The cycle dose is simply an estimate of the total number of cycles of fold tissue oscillation, calculated from both the elapsed phonation time data and the average fundamental frequency for the time period of interest (for example, 5 minutes or 300 seconds of phonation at an average fundamental frequency of 200 Hz or cycles per second would result in a cycle dose of 60,000 cycles). …
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