Estella P.-M. Ma

Electroglottographic Evaluation of Age and Gender Effects During Sustained Phonation and Connected Speech

The aim of the present study was to evaluate the effects of age and gender on selected vocal fold vibratory behaviors during vowel prolongation and connected speech using electroglottography (EGG). Forty-six young and older individuals (23 males and 23 females) with normal voices participated in this study. EGG parameters including fundamental frequency and contact quotient were measured during sustained vowel prolongation and connected speech tasks. Significant age-by-gender interactions were found for both parameters. Moreover, results from discriminant function analyses revealed that the overall accuracies of the parameters in predicting different age and gender groups were higher for the connected speech tasks than for the sustained vowel prolongation task (89.1% and 73.9% for passage and phrase tasks vs 71.7% for vowel prolongation). These findings suggest that reliability of EGG measures can be affected by the test stimuli. Therefore, one should carefully consider the use of the speech material when assessing vocal fold behaviors using EGG. The findings also support the use of connected speech stimulus, preferably at passage level, in electroglottographic evaluation for a better representation of vocal fold vibrating behaviors.

Suitability of Acoustic Perturbation Measures in Analysing Periodic and Nearly Periodic Voice Signals

In recent years, acoustic perturbation measurement has gained clinical and research popularity due to the ease of availability of commercial acoustic analysing software packages in the market. However, because the measurement itself depends critically on the accuracy of frequency tracking from the voice signal, researchers argue that perturbation measures are not suitable for analysing dysphonic voice samples, which are aperiodic in nature. This study compares the fundamental frequency, relative amplitude perturbation, shimmer percent and noise-to-harmonic ratio between a group of dysphonic and non-dysphonic subjects. One hundred and twelve dysphonic subjects (93 females and 19 males) and 41 non-dysphonic subjects (35 females and 6 males) participated in the study. All the 153 voice samples were categorized into type I (periodic or nearly periodic), type II (signals with subharmonic frequencies that approach the fundamental frequency) and type III (aperiodic) signals. Only the type I (periodic and nearly periodic) voice signals were acoustically analysed for perturbation measures. Results revealed that the dysphonic female group presented significantly lower fundamental frequency, significantly higher relative amplitude perturbation and shimmer percent values than the non-dysphonic female group. However, none of these three perturbation measures were able to differentiate between male dysphonic and male non-dysphonic subjects. The noise-to-harmonic ratio failed to differentiate between the dysphonic and non-dysphonic voices for both gender groups. These results question the sensitivity of acoustic perturbation measures in detecting dysphonia and suggest that contemporary acoustic perturbation measures are not suitable for analysing dysphonic voice signals, which are even nearly periodic.

An introduction to the International Classification of Functioning, Disability and Health (ICF) for speech-language pathology: Its past, present and future

This paper provides a context for the remainder of this special issue on the International Classification of Functioning, Disability and Health (ICF) and speech-language pathology. It describes the ICF—its past, present and future in relation to the discipline of speech-language pathology. The history of the ICF is presented outlining the characteristics of previous versions of the ICF. In particular the changes to the terminology are described. The current status of the ICF is then depicted, with an emphasis on how the ICF has been operationalized in areas that affect speech-language pathology. The final section summarizes three challenges related to the application of the ICF in speech-language pathology: quickening its translation into clinical practice, developing better agreement on specific classifications relevant to the profession, and finally achieving a full roll out of the broad scope of the ICF in the profession.

Scaling voice activity limitation and participation restriction in dysphonic individuals.

The purpose of this study was to determine the most appropriate scaling procedure for evaluating voice activity limitation (AL) and voice participation restriction (PR). In a randomly counterbalanced design, 32 dysphonic individuals rated their self-perceived extents of voice AL and PR using two scaling procedures [equal-appearing interval (EAI) scaling and visual analogue (VA) scaling]. Results revealed that test-retest reliabilities were similar for the two scaling procedures. The overall extents of voice AL and PR obtained from the two scaling procedures were similar. Moreover, the significant linear relationships obtained between the EAI and VA data of voice AL and PR suggest both dimensions as metathetic in nature. Therefore, either EAI or VA scaling procedure would be considered as appropriate for rating voice AL and PR. However, the relative ease to use by consumers favours the choice of EAI over VA scaling procedure for evaluating voice AL and PR.

Effects of Practice Variability on Learning of Relaxed Phonation in Vocally Hyperfunctional Speakers

The present study investigated the effects of practice variability on the learning of relaxed phonation using a motor learning perspective. Twenty-one individuals with hyperfunctional voice problems were evenly and randomly assigned to three groups of practice conditions: constant, blocked, and random practice conditions. During training, participants in the constant practice condition were asked to read aloud sentence stimuli with four Chinese characters. Participants in the blocked practice condition were asked to read aloud sentence stimuli with increasing sentence length, starting from sets of two characters to five characters. Participants in the random practice condition were asked to practice reading sentence stimuli of variable length from two to five characters presented in a random fashion. Surface electromyographic feedback (sEMG) from the thyrohyoid muscle site was given to each participant after reading every two sentence stimuli. Results demonstrated that for all the participants, voice motor learning was evidenced by the decreased sEMG levels in delayed retention test. Generalization to untrained passage was shown as well. However, results did not reveal any difference in the learning among the three practice conditions. The findings from the present study did not support the hypothesis of contextual interference, which states that practice using variable items presented in a random mode is more beneficial to learning than practice using constant items.

Speech Intelligibility, Acceptability, and Communication-Related Quality of Life in Chinese Alaryngeal Speakers

OBJECTIVE To investigate (1) speech intelligibility and acceptability in using 4 different alaryngeal speech methods: esophageal (ES), electrolaryngeal (EL), pneumatic device (PD), and tracheosophageal (TE) speech; and (2) communication-related quality of life (QOL) in the alaryngeal speakers who used these 4 alaryngeal speech methods. DESIGN Survey. PARTICIPANTS Alaryngeal speakers who had undergone speech rehabilitation and were recruited from the New Voice Club of Hong Kong. MAIN OUTCOME MEASURES Speech samples collected from 49 alaryngeal speakers were rated by 6 judges for speech intelligibility and acceptability. The speakers also completed a communication-related QOL questionnaire called the Communication Activity and Participation After Laryngectomy. RESULTS We found that the ES and EL speakers showed considerably poorer speech intelligibility and communication-related QOL. The PD speakers demonstrated notably better speech intelligibility and acceptability ratings. However, high intelligibility and acceptability do not necessarily mean better QOL. The TE speakers, who demonstrated only the second highest speech intelligibility and acceptability, showed the best functional QOL. CONCLUSION In speech rehabilitation after laryngectomy, QOL and speech intelligibility and acceptability should be considered together to find a balance that is acceptable to the patient.

Effects of practice schedules on speech motor learning

Abstract The aim of this study was to evaluate the effects of various practice schedules on learning a novel speech task. Forty healthy Cantonese speakers were asked to learn to produce a Cantonese phrase with two target utterance durations (2500 and 3500 milliseconds). They were randomly assigned to one of four learning conditions, each completing a different practice schedule, namely Blocked only, Random only, Blocked-then-Random, and Random-then-Blocked. Two retention tests (one immediate and one delayed) and a transfer test were administered. The four groups of participants showed different patterns of learning, but achieved comparable levels of performance at the end of the acquisition phase. However, participants in the Blocked only condition were less able to differentiate the two target durations than those in the Random only condition during retention. Furthermore, participants who received both blocked and random practice were less adversely affected by the secondary task during the transfer test than those who received either blocked or random practice alone. These findings suggest that mixed practice schedules are more effective than either blocked or random practice, especially in transferring the acquired speech motor skills to a cognitively demanding situation. The results have clinical implications regarding optimal practice schedules for treatment intervention.

A systematic review and meta-analysis on acoustic voice parameters after uncomplicated thyroidectomy

Postthyroidectomy voice changes are common even without apparent laryngeal nerve injury. Our study evaluated the impact of open cervical thyroidectomy on five acoustic voice parameters in the early (< 3 months) and late (≥ 3 months) postoperative periods.

Analogy Instruction and Speech Performance Under Psychological Stress

To examine the efficacy of explicit and implicit forms of instruction for speech motor performance under conditions of psychological stress. In experiment 1, 20 participants were asked to deliver a formal presentation to validate the modified Trier Social Stress Test (TSST). In experiment 2, 40 participants were instructed explicitly by verbal explanation or implicitly by analogy to speak with minimum pitch variation and were subjected to psychological stress using the modified TSST. Acoustic correlates of pitch height (mean fundamental frequency) and pitch variation (standard deviation of fundamental frequency) significantly increased in experiment 1 when participants delivered a speech under modified TSST condition. In experiment 2, explicitly instructed participants were unable to maintain minimum pitch variation under psychological pressure caused by the modified TSST, whereas analogy-instructed participants maintained minimal pitch variation. The findings are consistent with existing evidence that analogy instructions may result in characteristics of implicit motor learning, such as greater stability of performance under pressure. Analogy instructions may therefore benefit speech motor performance and might provide a useful clinical tool for treatment of speech-disordered populations.

Single-session high intensity focussed ablation (HIFU) versus open cervical hemithyroidectomy for benign thyroid nodule: analysis on early efficacy, safety and voice quality

Abstract Background: High intensity focussed ultrasound (HIFU) is a promising non-surgical treatment for symptomatic benign thyroid nodule. We aimed to compare early efficacy, safety and voice quality between HIFU ablation and open thyroidectomy. Methods: Consecutive patients who underwent single-session HIFU ablation or a hemithyroidectomy for symptomatic benign thyroid nodule were included. The 6-month extent of nodule shrinkage, symptom improvement score, thyroid function, hospital stay and cost were compared between the two procedures. Safety was defined by absence of major complications like recurrent laryngeal nerve injury and skin burn. Voice quality was assessed by a computerised multi-dimensional voice programme and a Voice Handicap Index (VHI) questionnaire 1-month after treatment. Results: Altogether, 43 patients had HIFU and 103 patients had a hemithyroidectomy. In the HIFU group, the extent of nodule shrinkage at 6-month was 51.71 ± 16.04%. No patients in the HIFU group suffered skin burn or hypothyroidism. The HIFU group had a significantly shorter length of hospital stay (0.3 vs. 1.0 day, p < 0.001), lower incidence of subclinical hypothyroidism (1/43 vs. 21/103, p = 0.008), higher symptom improvement score (p = 0.009) and was less costly (USD 1923.1 vs. USD 5384.6). Relative to HIFU, pitch quality also worsen after surgery (p < 0.05). Conclusions: Relative to surgery, single HIFU ablation appeared efficacious and safe. Apart from shorter hospital stay, less subclinical hypothyroidism, being scar-less, lower cost and more symptom improvement, HIFU patients were less affected by a pitch problem in the first month. This study provides a strong argument for HIFU ablation as a treatment for symptomatic benign thyroid nodule.