Maximum Phonation Time in Healthy Older Adults

Objectives/Hypothesis

Maximum phonation time (MPT), a clinical measurement of the longest time one can phonate a vowel, typically /a/, is a frequently used measure of vocal function, but normative data are lacking for MPT in healthy older adults. The aim of this study was to provide data on MPT in healthy older adults and to determine the effect of advanced age, gender, and repeated measures on MPT.

Study Design

Prospective.

Methods

Sixty-nine healthy older adult volunteers participated (ie, 15, 26, and 28 in the seventh, eighth, and ninth decades of life, respectively). The effects of age, gender, and repeated measures (three trials in a single session) on MPT were assessed. Mean, standard deviation, compound symmetry covariance, analysis of variance, and analysis of covariance were used for statistical analysis.

Results

Neither age group, gender, trial, nor their interactions was statistically significant (P > 0.05). Adults in the seventh, eighth, and ninth decades of life had mean MPTs of 22.27 (standard error [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), respectively.

Conclusions

MPTs were longer in this group of older adults than previously reported and did not vary significantly with age or gender. Additionally, across a single short sampling session, measurements were relatively stable across three trials of MPTs.     

Exercise physiology principles applied to vocal performance: The improvement of postural alignment

Postural alignment is not an inherent trait. Proper alignment is acquiredthrough training postural muscle groups. This training is based on scientific principles associated with improving the physiological parameters of muscle mechanics. The purpose of this report is to describe and demonstrate the application of exercise physiology training principles to the improvement of postural alignment, which may enhance vocal performance. Specific exercise principles are explained and key concepts highlighted. Selected exercises for training postural muscles are presented to assist in establishing techniques that result in the expected adaptations. The application of training principles to postural muscles has been shown to improve postural alignment by strengthening synergistic muscles and establishing a balance between the agonistic and antagonistic activity of these muscles. Since posture has been well established as an important component of vocal performance, the application of these principles to vocal training seems to warrant the attention of vocal trainers and performers.     

Aging Effects on the Structure Underlying Balance Abilities Tests

Balance impairment is one of the biggest risk factors for falls reducing inactivity, resulting in nursing care. Therefore, balance ability is crucial to maintain the activities of independent daily living of older adults. Many tests to assess balance ability have been developed. However, few reports reveal the structure underlying results of balance performance tests comparing young and older adults. Covariance structure analysis is a tool that is used to test statistically whether factorial structure fits data. This study examined aging effects on the factorial structure underlying balance performance tests. Participants comprised 60 healthy young women aged 22 ± 3 years (young group) and 60 community-dwelling older women aged 69 ± 5 years (older group). Six balance tests: postural sway, one-leg standing, functional reach, timed up and go (TUG), gait, and the EquiTest were employed. Exploratory factor analysis revealed that three clearly interpretable factors were extracted in the young group. The first factor had high loadings on the EquiTest, and was interpreted as ‘Reactive’. The second factor had high loadings on the postural sway test, and was interpreted as ‘Static’. The third factor had high loadings on TUG and gait test, and was interpreted as ‘Dynamic’. Similarly, three interpretable factors were extracted in the older group. The first factor had high loadings on the postural sway test and the EquiTest and therefore was interpreted as ‘Static and Reactive’. The second factor, which had high loadings on the EquiTest, was interpreted as ‘Reactive’. The third factor, which had high loadings on TUG and the gait test, was interpreted as ‘Dynamic’. A covariance structure model was applied to the test data: the second-order factor was balance ability, and the first-order factors were static, dynamic and reactive factors which were assumed to be measured based on the six balance tests. Goodness-of-fit index (GFI) of the models were acceptable (young group, GFI=0.931; older group, GFI=0.923). Static, dynamic and reactive factors relating to balance ability had loadings 0.21, 0.24, and 0.76 in the young group and 0.71, 0.28, and 0.43 in the older group, respectively. It is suggested that the common factorial structure of balance abilities were static, dynamic and reactive, and that for young people reactive balance ability was characterized and explained by balance ability, whereas for older people it was static balance ability.     

Opportunistic spectrum access for TDMA-based cognitive radio networks

In this paper, opportunistic spectrum access is proposed for TDMA-based cognitive radio networks. In TDMA-based networks, the time is divided into slots with fixed length one by one. If a primary user (PU) needs to transmit data, one or several slots will be used. Otherwise, the slots are idle and can be utilized by secondary users (SUs). When SUs want to use the licensed channel, they should sense the channel at the beginning period of each slot. Then SUs exchange their sensing results and make the same decision about the channel state (idle or used by PUs), which could reduce the probability of false sensing. The aforementioned duration is called spectrum sensing phase. When SUs decide there is an idle channel, they contend to use the channel at the rest time of the slot. The duration is called access phase. In this period, SUs contend the channel with backoff counters. When the remaining time is less than one data transmission duration, SUs cannot transmit data packets. Therefore, the remaining time is wasted. To solve this problem, SUs transmit control packets with small length in the remaining time instead. The SU who exchange control packets successfully reserves the channel and sends a data packet prior to other SUs in access phase of the next idle slot. Obviously, this reserved transmission is without collision. The independent spectrum sensing, channel state decision and control packets reservation influence the performance of SUs. The proposed scheme is formulated with all above factors. Simulations which consist with the numerical results show the proposed access scheme achieve higher throughput than the existed scheme without channel reservation.     

Considerations for Maintenance of Postural Alignment for Voice Production

There is general agreement that postural alignment is important in optimizing voice function. A number of articles have illuminated the way in which posture, particularly of the cervical spine, is directly related to vocal resonance and pitch control. Despite frequent involvement in muscle training, few speech pathologists have the background in exercise physiology necessary to appreciate the contribution of muscular length-tension relationships to postural alignment. The purpose of this article is to provide voice therapists with information to help them formulate appropriate recommendations for improving postural alignment. This article synthesizes information from the literature regarding the role of muscular length-tension balance in the attainment and maintenance of postural alignment. Important considerations in the assessment of muscle tension and weakness are presented along with advice regarding application to the treatment of voice-disordered patients. Concepts detailed include agonist/antagonist relationships, the biomechanics of stretching, postural assessment, and the relationship between muscle tension and muscle weakness. The role of both stretching and strength-based training is discussed. Specific exercises with emphasis on altering the alignment of the cervical and thoracic spine are presented with suggestions for their use in the clinic. There is growing understanding of the physiology behind recommendations of voice teachers and therapists to maintain optimal alignment. To effectively mediate postural misalignment, clinicians must have knowledge of the length-tension relationships between muscles. This understanding will lead to better interventions for postural alignment.     

The role of cognitive cueing in eliciting vocal variability

Variation in duration and frequency during three readings of each of eight sentences by 9 normal and 4 voice-disordered subjects are compared. Instructions to the subjects varied with respect to the amount and type of cognitive cueing presented in the trials, and the sentences were read in random order. Variability in fundamental frequency (F₀) was greater when pitch variation was specifically cued. Also, the portion of the sentence that was cued had greater variability in F₀ than other parts of the sentence. Variation in fundamental frequency was significantly greater in the cued versus uncued sentence trials for the voice-disordered subjects but not for the normal subjects. However, all subjects exhibited significantly greater duration for cued versus uncued readings of the same sentences. Implications for theory and practice are discussed.