Flow Phonation Research Articles

Preliminary Perceptual Findings of Singing After Flow Phonation Voice Exercises for Singers in Training

Goals of voice therapy and vocal pedagogy share similar principles and therefore, therapy approaches designed to improve the disordered voice may be equally effective when used to enhance healthy voice and vice versa. The purpose of this study was to investigate the effects of flow phonation voice exercises on vocal characteristics of students in undergraduate vocal music training programs and examine their potential use in vocal pedagogy. A total of 10 cis females were recruited and were randomized into two groups: an experimental group (group 1, n=6) receiving five sessions of flow phonation intervention across 5weeks; and a control group (group 2, n=4) that did not receive any direct intervention other than vocal hygiene education. Participants provided data pertaining to auditory perception, subjective respiratory measures, voice-related quality of life, and vocal fatigue before and after 5weeks. Flow phonation exercises consisted of cup bubble blowing, gargling, and stretch and flow. Wilcoxon signed ranks test was administered to compare outcomes across time points and between groups. Data indicate statistically significant changes in auditory perception of the singing voice, and voice-related quality of life for the group that received flow phonation exercises alone. No other measures showed statistical significance. Overall, this study indicates that the use of flow phonation voice exercises has the potential to improve voice instruction within the voice studio. While our target enrollments were not met to achieve optimal statistical power, our hypotheses were at least partially supported. In particular, positive intervention-related changes were observed in self-perceived voice handicap, and auditory perception of singing which were not observed in the control group.

A randomized controlled trial of the effects of flow phonation voice treatment for primary muscle tension dysphonia

ObjectiveThe purpose of the study was to investigate the effects of flow phonation voice therapy on laryngeal physiology and vocal quality in persons with primary Muscle Tension Dysphonia (MTD1). MethodsSeventeen participants with a diagnosis of MTD1 completed the study. Participants were randomized to two groups. Group 1 (9 participants) received flow phonation treatment and individualized vocal hygiene education for 12 sessions over six weeks. Group 2 (8 participants) received vocal hygiene education only for three weeks (6 sessions), followed by another three weeks (6 sessions) of both vocal hygiene instruction and flow phonation therapy. Treatment consisted of cup-bubble blowing, gargling, and stretch and flow exercises. Visual-perceptual. auditory-perceptual, acoustic, aerodynamic and voice-related quality-of-life measures were obtained at three time points: before treatment, three weeks after initiation of treatment and after completion of treatment. ResultsVoice quality was perceived to be significantly improved in both groups. Voice related quality-of-life trended toward improvement for both groups across time points. Changes in aerodynamic and acoustic measures did not reach statistical significance compared to baseline for both groups. Visual comparisons of laryngeal closure patterns demonstrated comparably better outcomes for Group 1. ConclusionsResults of this study indicate flow phonation exercises can potentially be favorably employed for individuals with MTD1. In particular, it appears that the exercises aid in alleviating vocal hyperfunction, as evidenced by visual perceptual stroboscopic analysis, and clinically improved auditory-perceptual measures.

Glottal Airflow and Glottal Area Waveform Characteristics of Flow Phonation in Untrained Vocally Healthy Adults

To examine flow phonation characteristics with regard to vocal fold vibration and voice source properties in vocally healthy adults using multimodality voice measurements across various phonation types (breathy, neutral, flow, and pressed) and loudness conditions (typical, loud, and soft). Vocal fold vibration, airflow, acoustic, and subglottal pressure was analyzed in 13 untrained voices (six female and seven male). Participants repeated the syllable / pæ:/ using breathy, neutral, flow, and pressed phonation during typical, loud, and soft loudness conditions. Glottal area (GA) waveforms were extracted from high-speed videoendoscopy; glottal flow was derived from inverse filtering the airflow or the audio signal; and subglottal pressure was measured as the intraoral pressure during /p/ occlusion. Changes in phonation type and loudness conditions resulted in systematic variations across the relative peak closing velocity derived from the GA waveform for both males and females. Amplitude quotient derived from the flow glottogram varied across phonation types for males. Multimodality evaluation using the GA waveform and the inverse filtered waveforms revealed a complex pattern that varied as a function of phonation types and loudness conditions across males and females. Emerging findings from this study suggests that future large-scale studies should focus on spatial and temporal features of closing speed and closing duration for differentiating flow phonation from other phonation types in untrained adults with and without voice disorders.

Effects of Voice Therapy for Dysphonia due to Tension Imbalance in Unilateral Vocal Fold Paralysis and Paresis

Medialization procedures, such as type I thyroplasty, arytenoid adduction, and vocal fold injection, are popular treatments for dysphonia due to unilateral vocal fold paralysis (UVFP). However, dysphonia occasionally persists after medialization procedures owing to tension imbalance. This tension imbalance causes diplophonia, asymmetry and aperiodic vibrational flutter in travelling wave motion. Currently, there is no established treatment for tension imbalance. We herein report two cases with residual dysphonia due to tension imbalance following medialization for chronic UVFP, and another case presenting with dysphonia due to tension imbalance following chronic unilateral vocal fold paresis. Three patients underwent voice therapy using flow phonation to facilitate increased airflow management in speech as well as forward oral resonance by focusing on balanced airflow. Phonatory outcomes were evaluated using stroboscopic findings, aerodynamic and acoustic measures, as well as self-rating. Aerodynamic assessments, acoustic findings and self-ratings improved in all three cases after voice therapy. Stroboscopic findings prior to voice therapy showed asymmetric vibration with glottic gap, which was improved after voice therapy. Fundamental frequency (F0) also increased post-therapy. In a previous canine study, it was shown that enhanced breath support with expiratory airflow resulted in increased F0, suggesting that enhanced breath support could increase vocal fold tension. The increased F0 achieved in the present cases following voice therapy may increase vocal fold tension with breath support. Thus, voice therapy using flow phonation may be effective for supporting vocal fold tension and improving dysphonia due to tension imbalance following UVFP and paresis.

Aerobic Exercise as a Warm-up for Singing: Acoustic Impacts

In a previous work, it was found that a 30-minute aerobic workout significantly increased singers' sound pressure level and airflow during voicing, suggesting a shift to flow phonation. This companion study was designed to assess the impact of the same workout on pitch accuracy, vibrato rate, extent and regularity, and the singing power ratio. This study is a cohort experimental study. Twenty-two students in an academic vocal performance program participated. They performed an aerobic workout for 30 minutes. Before and after the workout, they sang the first seven notes of the "Star-Spangled Banner" on /pa/, producing seven /pa/s on the last note. The students then sang an ascending and descending scale to the ninth on "ah." The following measures were obtained from the "Star-Spangled Banner": pitch accuracy calculated on the seventh note ("by"); and vibrato rate, regularity, and extent, calculated on the most sustained sixth note ("see"). For the scale, the following measures were calculated from each note: pitch accuracy; vibrato rate, regularity, and extent; and the singing power ratio. There were no significant differences from pre- to postworkout across any measures. It appears that an aerobic workout positively impacts the respiratory driving force for voice production but does little for phonation. Critical for performance is the fine tuning and balancing across the respiratory, laryngeal, and resonance systems. It appears that this can only be achieved with vocalization exercises, facilitating coordination within and across the physiological systems involved in the complex art of bel canto.

Phonatory Strategies of Male Vocalists in Singing Diatonic Scales With Various Dynamic Shapings

This work aimed to investigate glottal adduction in the case of the singing of diatonic D major ascending scales with different dynamic shapings on vowel [a:] by 10 classically trained male singers. The parameters obtained by inverse filtering-closed quotient (CQ), normalized amplitude quotient (NAQ), and the level difference between the first two partials of the glottal flow waveform spectrum (H1-H2)-all indicated statistically significant systematic changes when singers sang (1) with habitual dynamics without intentional dynamic changes; (2) with sempre crescendo from piano to forte; and (3) with sempre diminuendo from forte to piano. Adduction on average was lower if the tone with the same pitch was sung piano compared with when it was sung forte. The piano tones with the limit of one and the same dynamic task were sung with lower adduction on average compared with one octave higher or lower tones sung forte, although here the agreement between different parameters was poorer and the individual variability was greater. There was only a moderate negative correlation between CQ and NAQ (r = -0.41) but a strong negative correlation between CQ and H1-H2 (r = -0.8). CQ showed a moderate positive correlation with sound level but no significant correlation with pitch. NAQ showed a strong and significant positive correlation with pitch but not with sound level (except when it was calculated only at constant pitch). Some of the most experienced singers used quite high glottal adduction levels, questioning the concept of whether flow phonation is always the favorite classical style.

Telepractice Versus In-Person Delivery of Voice Therapy for Primary Muscle Tension Dysphonia.

The purpose of this study was to investigate the utility of telepractice for delivering flow phonation exercises to persons with primary muscle tension dysphonia (MTD). Fourteen participants with a diagnosis of primary MTD participated, 7 on site and 7 at remote locations. Each participant received 12 treatment sessions across 6 weeks. Treatment consisted of flow phonation voice therapy exercises. Auditory-perceptual, acoustic, aerodynamic, and quality-of-life measures were taken before and after treatment. Perceptual and quality-of-life measures were significantly better posttreatment and were statistically equivalent across groups. Acoustic and aerodynamic measures improved in both groups, but changes did not reach statistical significance. Results for the 2 service delivery groups were comparable, with no significant differences observed for perceptual and quality-of-life measures. Although the American Speech-Language-Hearing Association supports the use of telepractice for speech-language pathology services, evidence for the use of telepractice for providing behavioral treatment to patients with MTD has been lacking. The results of this study indicate that flow phonation exercises can be successfully used for patients with MTD using telepractice.

Treatment of dysphonia in older people: the role of the speech therapist.

This review addresses speech therapy interventions for older adults experiencing voice impairments. The prevalence, impact, and nature of voice impairments in older people are outlined. Intervention methods and their effectiveness are discussed, with particular focus on behavioral treatments for presbyphonia. The strength of current evidence is discussed and recommendations for future research are presented. There has been a substantial increase in the number of older people seeking voice management over the last 10-20 years. Reduced vocal effectiveness in older people is likely to be multifactorial and associated with normal physiological aging, maladaptive responses to vocal aging, and medical and psychosocial conditions that are common in older age. Although several authors have claimed that behavioral intervention for presbyphonia is effective, few studies were reported until 2008. Since then, 10 studies have been published as to the effectiveness of behavioral interventions for age-related dysphonia. Voice therapy techniques evaluated include vocal function exercises, phonation resistance training exercise, Lessac-Madsen resonant voice therapy, Lee Silverman voice treatment, neuromuscular electrical stimulation, semi-occluded vocal tract, and flow phonation. Findings suggest that behavioral interventions for presbyphonia have the potential to mitigate effects of vocal aging, but the overall evidence base is inadequate to allow definitive conclusions. Because vocal effectiveness diminishes as people age and because diminished vocal capabilities are associated with negative impacts, the importance of establishing whether behavioral interventions are effective is now acknowledged. Although the number of studies on speech therapy interventions has increased, the body of evidence is limited and further research is required.

Quantifying Component Parts of Indirect and Direct Voice Therapy Related to Different Voice Disorders

Voice therapy changes how people use and care for their voices. Speech-language pathologists (SLPs) have a multitude of choices from which to modify patient's vocal behaviors. Six SLPs performed 1461 voice therapy sessions and quantified the percentage of time spent in eight component parts of indirect and four component parts of direct voice therapy across five common voice disorders. Voice therapy data collection forms were prospectively completed immediately following each therapy visit. The SLPs were free to choose the component parts of voice therapy best suited for their respective patients. Results showed that direct voice therapy represented more than 75% of the treatment time across all voice therapy sessions. In the components of direct voice therapy, there was no statistical difference between percentages of time spent in resonant voice and flow phonation across all voice disorders. However, a significant difference was found for the time spent addressing transfer to conversational speech for muscle tension dysphonia, lesions, and scar than for vocal immobility and atrophy. Interestingly, while SLPs used a more common approach to direct voice therapy across voice disorders, they tended to vary the use of indirect components of therapy across voice disorders with certain components being addressed in greater length for specific voice disorders. Collectively, these results indicate that although SLPs may individualize their approach to indirect voice therapy, when it comes to direct voice therapy, SLPs have a common approach to voice therapy regardless of voice disorder.

Treatment of laryngeal hyperfunction with flow phonation: A pilot study

Context: While clinical successes and descriptions have been reported in a few texts, no data exist to define the utility of flow phonation to improve voice quality in patients with laryngeal hyperfunction. Aims: To provide pilot data regarding the utility of three exercises (gargling, cup bubble blowing, and stretch-and-flow) to improve phonatory airflow during voicing in patients with laryngeal hyperfunction. Settings and Design: Outpatient Voice and Swallowing Center in a University Medical Center. Materials and Methods: Participants received five treatment sessions and were evaluated prior to treatment and after each session using a Phonatory Aerodynamic System to measure airflow during voicing tasks. Noise-to-harmonic ratio and perceptual voice measures were also obtained, as was self-perception of voice handicap. Statistical Analysis Used: Repeated All increased airflow and decreased laryngeal airway resistance over five sessions. Measures Analysis of Variance. Results: Six participants completed the protocol. All participants decreased self-perception of voice handicap and improved on noise-to-harmonic ratio and perceptual ratings of vocal quality. Conclusions: Data derived on a small sample of patients in an exploratory investigation suggest further research into the use of these three exercises to improve airflow with voicing and improve vocal quality in patients with laryngeal hyperfunction is warranted.

Describing different styles of singing: A comparison of a female singer's voice source in ''Classical'', ''Pop'', ''Jazz'' and ''Blues''

The voice is apparently used in quite different manners in different styles of singing. Some of these differences concern the voice source, which varies considerably with loudness, pitch, and mode of phonation. We attempt to describe voice source differences between Classical, Pop, Jazz and Blues styles of singing as produced in a triad melody pattern by a professional female singer in soft, middle and loud phonation. An expert panel was asked to identify these triads as examples of either Classical, Pop, Jazz or Blues. The voice source was analysed by inverse filtering. Subglottal pressure P s, closed quotient Q Closed, glottal compliance (ratio between the air volume contained in a voice pulse and P s ), and the level difference between Closed the two lowest source spectrum partials were analysed in the styles and in four modes of phonation: breathy, flow, neutral, and pressed. The same expert panel rated the degree of pressedness in the entire material. Averages across pitch were calculated for each mode and style and related to their total range of variation in the subject. The glottogram data showed a high correlation with the ratings of pressedness. Based on these correlations a pressedness factor was computed from the glottogram data. A phonation map was constructed with the axes representing mean adduction factor and mean P s, respectively. In this map Classical was similar to flow phonation, Pop and Jazz to neutral and flow phonation, and Blues to pressed phonation.

Phonatory control in male singing: A study of the effects of subglottal pressure, fundamental frequency, and mode of phonation on the voice source

This article describes experiments carried out in order to gain a deeper understanding of the mechanisms underlying variation of vocal loudness in singers. Ten singers, two of whom are famous professional opera tenor soloists, phonated at different pitches and different loudnesses. Their voice source characteristics were analyzed by inverse filtering the oral airflow signal. It was found that the main physiological variable underlying loudness variation is subglottal pressure (Ps). The voice source property determining most of the loudness variation is the amplitude of the negative peak of the differentiated flow signal, as predicted by previous research. Increases in this amplitude are achieved by (a) increasing the pulse amplitude of the flow waveform; (b) moving the moment of vocal fold contact earlier in time, closer to the center of the pulse; and (c) skewing the pulses. The last mentioned alternative seems dependent on both Ps and the ratio between the fundamental frequency and the first formant. On the average, the singers doubled Ps when they increased fundamental frequency by one octave, and a doubling of the excess Ps over threshold caused the sound pressure level (SPL) to increase by 8-9 dB for neutral phonation, less if mode of phonation was changed to pressed. A shift of mode of phonation from flow over neutral to pressed was associated with a reduction of the peak glottal permittance i.e., the ratio between peak transglottal airflow to Ps. Flow phonation had the most favorable relationship between Ps and SPL.