Vocal roughness and jitter characteristics of vowels produced by esophageal speakers

The Effectiveness of Vocal Hygiene Education With Resonant Voice Therapy for School-Aged Children With Vocal Nodules

OBJECTIVE

This study evaluated the effectiveness of vocal hygiene education with resonant voice therapy for school-aged children with vocal nodules.

STUDY DESIGN

A pre-test/post-test control group design was employed.

METHODS

Seventeen children aged between 6 and 9 years old with vocal nodules were randomly assigned to three groups: a treatment group, a placebo group and a control group. Children in the treatment group (n = 7) received six consecutive, weekly, one-hour sessions of vocal hygiene education with resonant voice therapy. Children in the placebo group (n = 5) received six consecutive, weekly, one-hour sessions on presentation skills training. Children in the control group (n = 5) did not receive any form of treatment. Subjective outcome measures included auditory-perceptual evaluation of overall dysphonia severity, the Pediatric Voice Handicap Index (pVHI) and the Children's Voice Handicap Index-10 (CVHI-10). Objective outcome measures included acoustic analysis of fundamental frequency, jitter, shimmer and noise-to-harmonic ratio.

RESULTS AND CONCLUSIONS

Significant improvements in perceptual ratings of overall dysphonia severity levels and pVHI scores were found in the treatment group. No significant changes in acoustic measures and CVHI-10 scores were noted in any of the three groups. Interestingly, an improvement in perceptual overall dysphonia severity levels at post-evaluation was observed in the no treatment control group.

Cell Yell!: Health Risks in Telehealth

Purpose

The purpose of this study was to determine if the use of visual feedback can overcome the absence of side tone to control for vocal quality changes, specifically loudness, with speakerphone use.

Method

Ten men and 10 women held two 5-min conversations in pairs under audio-only and audiovisual communication conditions. Acoustical data and a number of conversational collisions (communication partners trying to speak at the same time) under each condition were compared.

Results

There were no statistically significant differences in acoustical measures of voice quality between audio-only and audiovisual conversations; however, vocal intensity was consistently 4 times more powerful than average face-to-face conversational intensity during both conditions. The number of conversational collisions was significantly less for the audiovisual condition as compared to the audio-only condition.

Conclusion

Results suggest that visual feedback did allow for modulation of conversational flow (fewer conversational collisions) but did not allow for modulation of vocal quality. Visual feedback did not overcome the absence of side tone and resulted in the same increased conversational loudness observed during the audio-only condition. As a result, remote conversational partners such as clients and telehealth practitioners are more susceptible to developing vocal health issues.

The effect of experience on perceptual spaces when judging synthesized voice quality: a multidimensional scaling study

OBJECTIVES/HYPOTHESIS

The purpose of this study was to determine the effect of experience on the perceptual space of listeners when judging voice quality.

STUDY DESIGN

This was a within-subjects group design.

METHOD

Speech-language pathologists, singing voice teachers, speech-language pathology graduate students with and without experience with a voice client, graduate students who have completed a voice pedagogy course, and inexperienced served as listeners. Each participant rated the similarity of pairs of synthesized stimuli with systematically altered measurements of jitter, shimmer, and noise-to-harmonics ratio on a visual analog scale ranging from no similarity to extremely similar.

RESULTS

Results showed that participants with different levels and types of experience used different perceptual spaces (of additive noise and perturbation measures) when judging the similarity of stimulus pairs.

CONCLUSION

The conclusion was that perceptual spaces differ among individuals with different levels and types of experience when judging the similarity of pairs of stimuli with systematically altered acoustical measurements.

Acoustic Analysis of Voice: A Tutorial

This tutorial reviews acoustic methods that have been used to characterize vocal function. The most persuasive argument for the use of acoustic measures is that all of the information used by listeners to make judgments about speech is to be found in the acoustic signal. Acoustic methods have been used clinically to differentiate normal from abnormal voices, to aid in differential diagnosis, to evaluate the relative effectiveness of different treatment approaches, and to track progress in voice therapy. The measures discussed here focus on quantifying the degree of periodicity, the shape of the spectrum, and the range of vocal intensity.

Reaction times of normal listeners to laryngeal, alaryngeal, and synthetic speech

The purpose of this study was to compare listener processing demands when decoding alaryngeal compared to laryngeal speech. Fifty-six listeners were presented with single words produced by 1 proficient speaker from 5 different modes of speech: normal, tracheosophageal (TE), esophageal (ES), electrolaryngeal (EL), and synthetic speech (SS). Cognitive processing load was indexed by listener reaction time (RT). To account for significant durational differences among the modes of speech, an RT ratio was calculated (stimulus duration divided by RT). Results indicated that the cognitive processing load was greater for ES and EL relative to normal speech. TE and normal speech did not differ in terms of RT ratio, suggesting fairly comparable cognitive demands placed on the listener. SS required greater cognitive processing load than normal and alaryngeal speech. The results are discussed relative to alaryngeal speech intelligibility and the role of the listener. Potential clinical applications and directions for future research are also presented.

The relationship between cepstral peak prominence and selected parameters of dysphonia

Traditional measures of dysphonia vary in their reliability and in their correlations with perceptions of grade. Measurements of cepstral peak prominence (CPP) have been shown to correlate well with perceptions of breathiness. Because it is a measure of periodicity, CPP should also predict roughness. The ability of CPP and other acoustic measures to predict overall dysphonia and the subcategories of breathiness and roughness in pathological voice samples is explored. Preoperative and postoperative speech samples from 19 patients with unilateral recurrent laryngeal nerve paralysis who underwent operative intervention were analyzed by trained listeners and by measures of smoothed CPP (CPPS), noise-to-harmonic ratio (NHR), amplitude perturbation quotient (APQ), relative average perturbation (RAP), and smoothed pitch perturbation quotient (sPPQ). The data were analyzed with bivariate Pearson correlation statistics. Grade of dysphonia and breathiness ratings correlated better with measurements of CPPS than with the other measures. CPPS from samples of connected speech (CPPS-s) best predicted overall dysphonia. None of the measures were useful in predicting roughness.

Comparison and evolution of perceptual and acoustic characteristics of voice after supracricoid partial laryngectomy with cricohyoidoepiglottopexy

The present prospective study, based on a series of 12 male patients managed with supracricoid partial laryngectomy with cricohyoidoepiglottopexy (SCPL-CHEP), was designed i) to compare the perceptual and acoustic parameters before surgery and at 6 months after sugery, ii) to evaluate the evolution of the perceptual and acoustic parameters between 6 and 18 months postoperatively, and iii) to determine the correlations between the perceptual and acoustic parameters preoperatively and at 18 months postoperatively. The roughness was found to be significantly worsened after SCPL-CHEP. The jitter, shimmer, noise-to-harmonic ratio, and degree of voiceless increased significantly after SCPL-CHEP. Neither acoustic nor perceptual parameters varied significantly between 6 and 18 months postoperatively. Preoperatively, a strong statistical correlation was found between grade, roughness and strain and all acoustic parameters but F0. Breathiness was statistically correlated with all acoustic parameters but jitter. Postoperatively the only statistical correlation noted was between roughness and F0.

Speech performance of adult cantonese-speaking laryngectomees using different types of alaryngeal phonation

The purpose of the present study was to compare the speech performance of four types of alaryngeal phonation-electrolaryngeal (EL), pneumatic artificial laryngeal (PA), tracheoesophageal (TE), and standard esophageal (SE) speech-by adult Cantonese-speaking laryngectomees. Subjective ratings of (1) voice quality, (2) articulation proficiency, (3) quietness of speech, (4) pitch variability, and (5) overall speech intelligibility were given by eight naive individuals who had no prior experience with any form of alaryngeal speech. Results indicated that SE and TE speech was perceived to be more hoarse than PA and EL speech. EL speech was associated with significantly less pitch variability, and PA speakers produced speech with the least amount of perceived noise. However, articulation proficiency and overall speech intelligibility were found to be comparable in all four types of alaryngeal speakers.

Performance effects on the voices of 10 choral tenors: acoustic and perceptual findings

Trained choral tenors performed a series of vocal tasks before and after a "live" performance. Acoustic (perturbation, harmonic-to-noise ratio, pitch and amplitude ranges) and perceptual analyses (auditory and proprioceptive/kinesthetic) were undertaken to detect changes from pre- to postperformance. Individuality of response to the performance was revealed, with the majority of subjects showing vocal deterioration after performance. The most sensitive vocal tasks were the comfortably pitched notes, high soft notes, and the bottom notes in scale singing. The most sensitive acoustic measure in detecting change from pre- to postperformance was harmonic-to-noise ratio. In contrast to the demonstrated acoustic changes, no significant differences in perceptual ratings were evident after the performance. Perceptual ratings did not reflect the acoustic analysis results. The present study highlights the need to establish further normative data for the singing voice and to consider individual differences in vocal characteristics in future studies of the singing voice.

Characteristics of voicing source waveforms produced by esophageal and tracheoesophageal speakers

Voicing source waveforms produced by 10 laryngectomized esophageal speakers, 12 laryngectomized tracheoesophageal speakers, and 10 age-matched, normal male speakers were obtained by inversely filtering flow functions recorded with a circumferentially vented mask. The data from these speakers was used to evaluate differences in source signal properties on a group basis. In a second analysis source signals produced by a single laryngectomized individual, capable of producing esophageal and tracheoesophageal speech in a highly proficient manner, were analyzed and compared. The overall results of this project provide an initial and novel description of voicing source signals produced by esophageal and tracheoesophageal speakers. The characteristics of these signals appear to be highly variable, particularly in comparison with the homogeneous pattern of source waves produced by age-matched, normal speakers. This initial description of voicing source signals produced by alaryngeal speakers is generally supportive of the hypothesis of differences in source properties among normal, esophageal, and tracheoesophageal voices.

Acoustic prediction of severity in commonly occurring voice problems

The relative effectiveness of three acoustic measures (jitter, shimmer, and harmonic/noise ratio) in predicting the dysphonic severity of a diverse clinical population singly and together was investigated. Phonatory samples were recorded from 20 normal subjects and 60 patients representing 3 laryngeal groups (nodules, paralysis, and functional). The phonatory samples were evaluated by 22 listeners using a 7-point equal-appearing interval scale. Shimmer produced a bivariate correlation of 0.54 with dysphonic severity; harmonic/noise ratio correlated -0.32 with dysphonic severity; and jitter produced no significant correlation with severity. The combination of acoustic variables through multiple regression analysis produced a correlation of 0.56, with only shimmer and average F0 contributing to the correlation. For this particular clinical population, therefore, findings indicated that (a) none of the variables was strongly correlated with dysphonia ratings, and (b) a combination of acoustic predictors was no more successful than a single predictor of dysphonic severity, namely, shimmer.

Perceptual evaluation of voice quality: review, tutorial, and a framework for future research

The reliability of listeners' ratings of voice quality is a central issue in voice research because of the clinical primacy of such ratings and because they are the standard against which other measures are evaluated. However, an extensive literature review indicates that both intrarater and interrater reliability fluctuate greatly from study to study. Further, our own data indicate that ratings of vocal roughness vary widely across individual clinicians, with a single voice often receiving nearly the full range of possible ratings. No model or theoretical framework currently exists to explain these variations, although such a model might guide development of efficient, valid, and standardized clinical protocols for voice evaluation. We propose a theoretical framework that attributes variability in ratings to several sources (including listeners' backgrounds and biases, the task used to gather ratings, interactions between listeners and tasks, and random error). This framework may guide development of new clinical voice and speech evaluation protocols, ultimately leading to more reliable perceptual ratings and a better understanding of the perceptual qualities of pathological voices.

Pitch perturbation measures of voice production of laryngectomees after the Amatsu tracheoesophageal shunt operation

Twenty tracheoesophageal speakers, 5 esophageal speakers, and 10 laryngeal speakers were subjected to pitch perturbation measurement in the sustained vowel production. Mean jitter, jitter ratio, average perturbation, and relative average perturbation were calculated from the successive vocal period. Jitter ratio values were 9.7 for laryngeal speakers, 29.6 for tracheoesophageal speakers, and 58.3 for esophageal speakers. Relative average perturbation values were 6.1 X 10(-3) for laryngeal speakers, 18.2 X 10(-3) for tracheoesophageal speakers, and 38.1 X 10(-3) for esophageal speakers. Results indicate that tracheoesophageal speech using exhaled pulmonary air is more stable than conventional esophageal speech.

Frequency perturbation characteristics of pulse register phonation

Examination of some acoustic characteristics of sustained pulse register phonation in normal adults confirmed the existence of two distinct waveform patterns. Trains of similar, highly damped waves with relatively uniform spacing predominated, but the "dicrotic" pattern previously described accounted for about 15% of the total sample. Average differences in the periods of continguous cycles (jitter) were extremely large--on the order of 20% of the fundamental period. Jitter did not vary with fundamental frequency according to the pattern documented in modal register and, thus, jitter ratio is not a useful normalizing descriptor of pulse register perturbation.

Directional perturbation factors for jitter and for shimmer

Directional perturbation factors for jitter and shimmer were calculated from the sustained production of the vowels /i/, /a/, and /u/ by 20 adult male and 20 adult female speakers. Directional factors for jitter were less than directional factors for shimmer. Shimmer directional factors for females had greater values than for the male speakers. Speculations on the relationship of directional factors and magnitude factors are made with reference to the laryngeal reflexogenic system. The usefulness of directional factors to early diagnosis of laryngeal disease are discussed.

Evaluation of alaryngeal voice quality by nonparametric procedures

Alaryngeal voice quality was evaluated based on nonparametric statistics. Twenty voice samples of the vowel /e/ were recorded from sixteen alaryngeal and four normal speakers, and were randomized and presented to twenty normal listeners. The listeners rated the voices using seven-point scales consisting of twelve pairs of polar-opposite adjectives. By means of nonparametric procedures such as the Wilcoxon signed rank test, significant differences in the rating scores were detected for certain combinations of the voice samples, the classes of voicing methods, the listeners and the rating scales. Quality of the alaryngeal voices differed significantly from that of the normal voices on some of the rating scales. The results suggest the nonparametric procedures are useful to evaluate alaryngeal voice quality.