Maximum Phonation Time in Healthy Older Adults
Introduction
Clinicians have many tools at their disposal to assess vocal function. Because of its simplicity and ease of use, maximum phonation time (MPT) is a frequently used clinical tool for assessing phonatory mechanics. MPT is the longest period during which a patient can sustain phonation of a vowel sound, typically /a/. A timer and audio recorder are the only equipment typically used to measure MPT. Many previous studies have used MPT to measure laryngeal function indirectly in different pathological circumstances, including patients with paralytic dysphonia1, 2 and those with weak or breathy voices.3 In patients with dysphonia, it has been used to objectively assess severity as well as to assess improvement after voice therapy.4 MPT has also been used to compare laryngeal function in healthy subjects and those with Parkinson’s disease.5 Because it is frequently used across various clinical contexts, it is important to have sufficient normative data on MPT for all age groups.
Although there are plenty of normative data on MPT in diverse subject populations, only a few studies have specifically examined MPT in older populations (65 and over). It is a commonly held assumption, however, that MPT varies with participant age.6, 7 Children tend to have shorter MPTs, require more trials to learn how to maximally phonate,8, 9 and show more variation than young adults.6 Young adults have less variation in MPT as a group and can phonate for a comparatively longer time than either children or older adults.6 The few research studies on MPT done in older adults have demonstrated a decrease in average MPT compared with younger adults (see Table 1 for a selected summary). As in children, MPT in young adults may improve with increasing numbers of trials,14 although there is evidence that three trials can elicit a reliable MPT if patients receive proper instructions and practice.15 The impact of increasing numbers of trials to elicit MPT has not been assessed specifically in older adults.
The purpose of this investigation was to measure MPT in healthy adult men and women aged 65 years and older and to determine if MPT varies by specific age group, gender, or the number of trials. Reliable normative data for healthy older adults can help guide clinical decisions when using MPT to assess laryngeal function in elderly patients with presumed laryngeal pathology.
Section snippets
Participants
Sixty-nine adult volunteers participated in this study (ie, n = 15, age 65–70; n = 26, age 71–80; and n = 28, age 81–90). There were 34 men and 35 women. Participants reported no history of swallowing, speech, or voice problems. All participants were in reported good health and denied any known neurologic or otolaryngologic disorders via written medical questionnaire. Volunteers were not screened for singing status or prior vocal training. The participant pool reflected a convenience sample of
Results
Unadjusted means of MPT by age group, gender, and trial are presented in Table 2. Adults in the seventh, eighth, and ninth decades of life had mean MPTs of 22.27 (SE = 1.56), 22.97 (SE = 1.11), and 21.14 (SE = 0.97) seconds, respectively. Females and males had mean MPTs of 20.96 (SE = 0.92) and 23.23 (SE = 0.96) seconds, respectively. Finally, MPTs for trials 1, 2, and 3 were 21.77 (SE = 1.09), 21.67 (SE = 1.12), and 22.80 (SE = 1.27) seconds, respectively.
The repeated measures ANOVA model indicates that
Discussion
Compared with previous results,5, 10, 11 we found that MPTs were substantially longer than previously described for patients aged 65 and older. Our study population was ambulatory and in good health; without any history of swallowing, speech, or voice problems; and no neurologic deficits. Although even healthy older adults should undergo natural decrements in physiological function because of weakening of the laryngeal and respiratory musculature, our results demonstrate that in healthy older
Conclusions
Given the limited amount of normative data on MPT in older adults, our results widen the spectrum of what should be considered a normal MPT in older adults without significant health problems or underlying laryngeal pathology. In this cohort of healthy older adults, many could phonate for at least 20 seconds in the absence of pathology. Three trials were sufficient for accurate MPT measures; and in this study population, the difference between genders was less evident compared with prior
Acknowledgments
This work was supported by National Institute on Deafness and Other Communication Disorders (R03 DC009875), the Wake Forest School of Medicine Claude D. Pepper Older Americans Independence Center (P30 AG21332), and the General Clinical Research Center of Wake Forest University Baptist Medical Center (M01-RR07122). Also, the authors thank Karen Potvin Klein, MA, ELS (Research Support Core, Wake Forest University Health Sciences) for her editorial contributions to this manuscript.
References (22)
Effects of voice therapy: a systematic review
J Voice
(2008)Maximum phonation time for children with normal voices
J Commun Disord
(1984)- et al.
Effect of age, gender, and repeated measures on intraoral air pressure in normal adults
J Voice
(2001) - et al.
Relation of lung volumes to height in healthy persons between the ages of 5 and 38 years
J Pediatr
(1961) Vocal rehabilitation of paralytic dysphonia: II. Acoustic analysis of vocal function
Arch Otolaryngol
(1955)Vocal rehabilitation of paralytic dysphonia: IV. Paralytic dysphonia due to unilateral recurrent nerve paralysis
Arch Otolaryngol
(1958)Speech Correction: Principles and Methods
(1954)Neuromuscular control examination (NMC) for Parkinsonism: vowel prolongations and diadochokinetic and reading rates
J Speech Hear Res
(1972)- et al.
Maximum performance tests of speech production
J Speech Hear Disord
(1987) - et al.
Vocal Aging
(2000)