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Voice Rest - Vocal Conservation as a Management Strategy (Non-operative and Post-op)

Return to: Handout: Voice ConservationSingers Packet (Voice Clinic Handouts)The Voice Clinic

Definitions:

I. Voice Rest:

"there is no established standard protocol " and "type and duration of of voice rest varies among clinicians" (Ishikawa 2010)

University of Iowa Voice Rest Strategy:

Rely heavily on the closer and often more frequent interactions between the patient and Speech Pathologist / Teacher of Singing / or Vocal Coach to tailor specifics in the context of more broadly provided recommendations by the Laryngologist.

IA. Voice Rest As Part of Non-Surgical Management

     a.  Voice Professionals with dysphonia (various lesions):

"Make no sound unless you are paid for it" (Vaughan and Gould 1988)

Excellent discussion with case examples addressing balance between need for singers to perform and also need to protect larynx (Stone 1994) includes: "modified voice rest means the use of a soft, easily produced whisper. It is not a stage whisper that is associated with increased laryngeal tension and a high flow rate."

See contemporary University of Iowa Voice Clinic: "Singers Packet" including Voice ConservationReflux Precautions, and Homeopathic Throat Soothers" as well as American Laryngologic Association "Patient Education" - https://alahns.org/research-education/voice-problems/

     b. Contact ulcer (vocal process granuloma)

"absolute silence, the patient writing every word he has to say" "even whispering should be forbidden" "If after two months of silence have failed to cure the ulcer, better to excise it..." (Jackson 1928)

"the patient should write everything he has to say except for about twenty words daily spoken in a low tone in a quiet place" "A good plan when the patient can afford it is to start on a long sea voyage and make no acquaintance on shipboard ... six months to a year, or someimes longer, is required... allowing twenty words a day; a little daily movement prevents degeneration of the laryngeal muscles" "the prognosis depends altogether on the faithfulness with which the regimen of vocal rest is obeyed" (Jackson and Jackson 1935)

"required complete vocal rest from 6 months to 1 year" (Ballenger and Ballenger 1957)

"use of conventional voice therapy, which included directions to eliminate the vocally abusive habits of coughing, excessive throat clearing, and shouting. None of the patients was instructed to institute complete voice rest" (Boch 1981 as cited in Hoffman 2003)

     c.  Phonotrauma Lesions (including nodules):

"Although relative voice rest can be helpful early in the course of speech therapy, absolute voice rest is rarely necessary"(Anderson 2007)

Strict voice rest (no whispering) for 7 days coupled with 5-7 day taper of oral steroids were used both as initial treatment in 141 singers with phonotraumatic lesions and then evaluated in a subset of 29 to study the value in this approach to help solidify the diagnosis with re-evaluation including stroboscopy on short term followup (three days after completing the regimen (Childs 2020). At that three day followup these 29 patients with ambiguous phonotrauma lesions were more specifically diagnosed a pseudocysts (5) nodules (3), scar (2), cyst (1) resolution (3) diagnosis unclear (4). This short-term (7 day) management resulted 86% of subjects showing overall improvement.

     d. Laryngitis

"Normal voice use with laryngitis is similar to hiking with blistered feet ...  Nevertheless, total voice rest is impractical and frustrating..." (Woodson 2003)

     e. Vocal cord (fold) hemorrhage

"Total voice rest without throat clearing is advised, although there is no definitive evidence confirming its efficacy. Cough suppressants are used when needed, as well as hydration" and "With early diagnosis, voice rest and follow-up with appropriate voice therapy and singing training, most patients achieve full recovery"(Paknezhad 2021)

Retrospective study of 47 instances of vocal fold hemorrhage with 12 recurrences (Lennon 2014)

35 with follow-up exam by telephone: none "who suffered a hemorrhage went on to develop a hemorrhagic polyp or other mucosal lesion, an observation that calls into question the assumption that such lesions are closely related or are part of a progression of phonotraumatic damage"

These investigators reported that "The presence of a vocal fold varix significantly increased the risk of recurrent hemorrhage; about half of patients with varices rehemorrhaged. This information allows appropriate counseling of patients and influences selection of patients for more intensive monitoring and/or treatment."

Conclude that "patients with vocal fold varices should be counseled appropriately, and if involved in activities that create significant phonotraumatic stress, be considered for ongoing monitoring, voice therapy (although we note that evidence that this decreases the chance of recurrence is lacking), and perhaps even surgical intervention."

     f. Reinke's Edema

The acute phonotrauma causing edematous changes to the vocal cords - "increased bilateral vocal folds edema following a loud reading task' (Welham 2003 citing Sher 1991) suggests that edema in Reinke's space may occur acutely and would logically respond to avoiding the injurious behavior that was associated. The term 'Reinke's edema' is most frequently used implying 'chronic Reinke's edema' but without using the term 'chronic'.

Our experience has found benefit with voice therapy to provide adaptive strategies for selective patients with chronic Reinke's space edema and differs from the assertion by Khodeir et al: "Voice therapy has no role in Reinke's edema, but it only could help in improving the patient's use of his/her voice after evacuation of Reinke's space" (Khodeir 2021)

IB. Post-Operative Voice Rest

a. "We recommend a 24-h period of relative voice rest for most patients" [after phonosurgery]; 'Voice rest beyond 1 week will be counter productive for most patients and should be avoided" (Ford and Bless 1991)  

b. "The efficacy of voice rest as therapy is unproven. Its wide standard use is based on anecdotal experience, and 'common sense'" and "Following surgery, our patients' first utternace is usually the /i/ in the examining chair approximately 1 week following surgery" (Sataloff and Spiegel 1993)

c. "... recommend 1 week of absolute voice rest in most casese, followed by strobovideolaryngoscopic evaluation .. [to] determine how rapidly a patient may increase voice use" and "typically gradually increase voice use over the following 2 to 6 weeks, under supervision of the voice team" (Rubin and Sataloff 2007)

d. "Patients were given strict instructions regarding voice rest, including no talking, throat clearing, or whispering." (see study by Rousseau et al 2011 below)

e. "After surgery of vocal folds, almost every patient will need some voice rest" "The present scientific evidence is scant but does not suport for prolonged (over 3 days) absolute voice rest after simple phonosugery"

"...relative voice rest...means that the person should speak softly, avoid long voicing, and restric speaking in noisy environment, on phone or outdoors to the minimum." (Rihkanen and Geneid 2019)

f. A simplified guideline to help resting the voice is to suggest 'the arms-length rule' of speaking in a low to moderate manner as if the listener is close enough to be within arms-length

II. Vocal Fatigue:  

   a. "A feeling of local tiredness and weak voice after a period of voice use" (Nanjundeswaran 2015)

   b. Appearance of voice symptoms that arise with voice use and resolve after voice rest (Narashimahn 2022)

                   Voice symptoms associated with vocal fatigue include laryngeal discomfort, increased vocal effort, vocal quality change, limited range or loudness (Moghtader 2019)

                    Vocal Fatigue Index - 19 point questionnaire addressing these symptoms reported to have good sensitivity and specificity (Nanjundeswaran 2014)

   c. ‘progressive increase in [presumably self-reported] phonatory effort accompanied by a progressive decrease in phonatory capabilities.’’ (McCabe 2002 as cited in Nanjundeswaran 2014)

   d. "negative vocal adaptation that occurs as a consequence of prolonged voice use." "Negative vocal adaptation is viewed as.... undesirable or unexpected changes in the functional status of the laryngeal mechanism" (Welham 2002)

'undesirable or unexpected changes' = symptoms of vocal fatigue: hoarse/husky vocal quality; breathy vocal quality; loss of voice; pitch breaks; inability to maintain typical ptich; reduced pitch range; lack of vocal carrying power; /reduced loudness range; need to use greater vocal effort; running ouf of breath while talking; unsteady voice; teneion in neck/shoulders; throat/neck pain; throat fatigue; throat tightness/constriction; pain on swallowing; increased need to cough/throat clear; discomfort in chest, ears back of neck (Welham 2002 citing Kostyk and Rochet 1998)

'Studies that have attempted to experimentally induce vocal fatigue in humans have yielded various and often conflicting results' (Welham 2002)

III. Voice Therapy

a. Definitions

Voice therapy is a program designed to reduce hoarseness through guided change in vocal behaviors and lifestyle changes. (ASHA 2022)

"Training new voice skills as well as training to replace old speech habits with new ones are crucial ingredients in voice therapy" (Ohlsson 2022)

Multiple voice therapy techniques may be used with a "typical voice treatment program includes voice ergonomics, relaxation, respiration, vocal exercises, and transfer-to speech." (Ohlsson 2022, Holmberg 2001, Niebudek-Bogusz 2008)

Vocal production therapy (sometimes called 'direct therapy') "involves exercises that may target one or more subsystems of voice production" with "specific techniques frequently vary" and is discriminated from "vocal hygiene education is an information-only approach" (Berman 2008). Through a randomized prospective study of 62 women with bilateral mid-fold lesions (nodules/pre-nodules/mid-fold swellings) Berman et al reported acomparison of VHE (vocal hygiene education) with VPT (voice production therapy) that included 6 weekly pirvate 45-minute sessions for both groups. The voice therapy group from the VHE group in the VHE subjects received no direct work on their voice and were not provided with vocal exercises. A primary outcome measured by repeating a VHI (voice handicap index) identified "VP [vocal production] therapy may be more effect than VHE [vocal hygiene education] (Berman 2008)

b. Voice Therapy Programs

The AAO-HNSF sponsored Clinical Practice Guideline addresing Hoarseness (Dysphonia) identified that "Voice therapy is underutilized in managing dysphonia despite efficacy" and "Voice therapy may be an important component of any comprhensive surgical treatmen tfor dysphonia" (Stachler 2018)

Duration and frequency of voice therapy - 

                          "... there is no standardized frame of reference on which prescribers and voice therapists can rely to estimate the therapy needs in terms of duration and frequency" (De Bodt 2015)

                                  Review of 140 studies (2,596 cases) identified an average of 11 sessions administered over an average of 9 weeks

                                 "Boot Camp" program of 1-4 days each wtih 4-7 hours of therapy by different therapists (Patel 2008)

                         A common approach 45 minute voice therapy sessions, one session a week for 6 weeks (Ohlsson 2022)

                         Standard at the U of Iowa Voice Clinic: "2 sessions per week for 6 weeks" with modifications as needed

Adherence to therapy program: "'behaviour-changing therapies, such as voice therapy, are only as effective as a patient's adherence" and " 38% of patients did not attend a voice evaluation after referral...47% of patients who attended a voice evaluation did not return for therapy" with reasons: insurance denial/distance traveled, lack of confidence in treatment (Hapner 2009)

IV. Vocal Hygiene

a. Definitions

Vocal Hygeine = ‘vocal well being, considering both the individual and the environment." "a broad concept, typically encompassiong all facets of optimal vocal health" (Behlau 2009)

b. Vocal Hygiene Programs (Vocal Hygiene Education)

education about vocal mechanisms / reducing phonotraumatic behaviors / identifying high-risk vocal situations / 'conservation of voice or vocal rest" (Behlau 2009), local lubrication and systemic hydration, optimal dietary consideations, controlling reflux and allergies (including LPR), minimize negative impact of environment/medications/lifestyle choices (including tobacco) (Watts 2015

Vocal Hygiene Education considered by some as adequate treatment of voice disorders without associated voice therapy - others relate that "Vocal hygiene should be considered only as a component of a broad vocal rehabilitation program" (Behlau 2009

"Vocal hygiene education considered an essential component of voice therpay for patients with phonotraumatic lesions of the vocal folds...sparse data are available, however, to support its effectiveness" (Berman 2008)

a randomized prospective study of 20 patients with muscle tension dysphonia randomized to treatment with 6 sessions of voice therapy (stretch-and-flow) over six weeks or non-treatment (control) with both groups receiving vocal hygiene education; significantly greater improvement was identified in the treatment group across multiple parameters (Watts 2015)

Background

Despite the common recommendation for voice rest, a consensus regarding the specifics of its application is still lacking. The intent of a panel of experts selected by the American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNS) was to produce an updated guideline addressing hoarseness (dysphonia) (Stachler 2018). This publication was designed "to reduce inappropriate variations in care  designed to assist clinicians by providing an evidence-based framework for decision-making strategies." Although this publication offers strong support for use of voice therapy under the care of speech pathologists, it contains no recommendations regarding the specific implementation of 'voice rest'

Enthusiasm for recommending absolute voice rest, or complete silence, has attenuated over the past decades with more recent studies suggesting there is questionabe benefit from this practice (Kaneko 2017) (Dhaliwal 2020). A prospective randomized study by Whitling et al comparing voice rest after phonosurgery classified as either 'relative' or 'absolute" identified that relative vocal rest resulted in better improvement in vocal stamina and long-term recovery than absolute voice rest (Whitling 2018).

Study in a canine model suggested that voice rest encourages re-epithelialization of the vocal cord mucosa - and has been used to support the hypothesis that voice rest aids the healing of vocal cord tissue to prevent worsening of injury or scarring (Cho 2000). However, recent evidence suggests that early mechanical stimulation (phonation) may actually improve healing (Kaneko 2017).

It is clear that vocal overuse compromises laryngeal function. Both subjective and objective voice assessments identified better voicing before voice use and after voice rest (overnight following a day of teaching) when compared to similar assessment following 4 hours of continuous class teaching by experienced secondary school teachers (Nanjundeswaran 2014).

Prevailing sentiment (2022) appears to support the value of  postoperative voice rest (vocal conservation) - often used in conjunction with voice therapy, hydration, and treatment of inciting factors (ie cough, throat clearing, infection) to facilitate healing.

Voice Rest (Non-Surgical) - Discussion

Phonotrauma, stress placed on the vocal cords causing injury, is often caused by vocal abuse (misuse / overuse). Increased stress on the vocal cords can cause inflammation, edema and possibly vocal cord hemorrhage. Voice rest is often a first-line empiric treatment for phonotrauma (Haben 2012). In the absence of a specific consensus statement regarding the specific voice rest recommendations, it is useful to review individual published opinions to help counseling.

If there are no gross findings on exam, relative voice rest continues to be commonly recommended for anywhere between a few days to months, depending on severity and expected outcomes. CM Haben suggested short term (7 days or less) of relative voice rest, followed by 1-4 weeks of gradual reintroduction of voice is appropriate for acute overuse in a previously healthy, asymptomatic patient (Haben 2012). Vocal therapy and voice hygiene are recommended to accompany the use of voice rest to help develop healthier use of the voice and prevent further/future injury. This approach has been emphasized for  patients with chronic overuse phonotrauma where changes of the lamina propria have occurred. Voice rest has been proposed to cause a 'deconditioning of the voice' with voice therapy thought to can help 're-condition the voice' (Haben 2012).

Voice Rest Associated with Surgery - Discussion

Factors such as vocal demands, extent and type of surgery as well as expectations help determine duration and intensity of vocal rest. A generalized and common recommendation has been for 5-7 days of voice rest (Joshi 2018).

More recent prospective studies have provided evidence that shorter durations of voice rest (or none at all) with a gradual ease into vocalization lead to better outcomes.

Kaneko et al found that 3 days of voice rest followed by voice therapy led to better wound healing compared to 7 days of voice rest (Kaneko 2017). 

Dhaliwal et al also found no difference in voice outcomes following phonosurgery in patients who underwent 7 days of voice rest vs patients with no voice rest (Dhaliwal 2020

Orthopedic rehabilitiation study has reported healing to improve with exercise when compare to long-term rest (Ishikawa 2010). However, these authors also point out the potential detrimental effect on healing of uncontrolled phonation - correlating it to the uncontrolled excessive mobilization may also impair orthopedic recovery.

Overall adherence to voice rest recommendations has been reported to be low - although it has been reported to be higher among patients post-surgery than for non-surgical indications. A signficant negative impact on the quality of life during the period of voice rest has been identified. (Rousseau 2011).

A sophisticated study by Misono et al employed a vocal dosimeter (accelerometer) applied to the anterior neck to assess vocal use compared in the two days preoperatively and then during the first two days postoperatively to assess vocal activity of patients who had been counselled regarding voice rest. (Misono 2015).

Counseling: "Patients were instructed to avoid any voice use, including speaking, shouting, singing, whispering, throat-clearing, and/or coughing"

Study: These investigators empoloyed a VocLog dosimater that stores up to 21 days of data - and records estimated decibels of phonation each second - including both voicing and non-speech phonatory behaviors such as throat-clearing and coughing. "Minor deception' was used to minimize bias by telling the patients the device measured neck muscle activity (refraining from telling them it measured voice use).

Results: The mean phonation percent was 29% preporcedure and 12% post-procedure (during voice rest) representing a reduction of voice use by 70% accompanied also by a halving the loudness of the voice (2.36 dB decrease in average sound level).

A prospective observational study of patients receiving in-office vocal fold procedures identified a greater adherence to vocal conservation (decreased talking) in the groups who had undergone preoperative voice therapy or counseling (one pre-procedure voice therapy session) when compared to the group that received neither (King 2021). 

Recommendations for work-excuse recommendations was included in a survey of postoperative voice rest practices and associated need for work absence (termed 'sick listing') was reported through a comparison of surveys sent to members of the Union of European Phoniatricians (UEP) in 2018 with a similar questionnaire sent to members of the European Laryngologica Society in 2012 (ELS) (Rihkanen 2019). Two sample cases (polyp removal in a teacher and mucosal repair of Reinke's oedema in a receptionist) presented to the respondents resulted in over 90% recommending absolute voice rest of 4-5 days (range 0-14 days) and sick leave ranging from 0 to 35 days. An average of 14 days of post-op sick leave was offered by UEP members for both surgical examples. The authors review of the literature identifed lack of scientific support for these recommendations - and conclude that "the evidence is scant, but does not support prolonged (over 3 days) absolute voice rest after simple phonosurgery"

Some of the difficulties in practicing voice rest was addressed through evaluating use of supplemental text-to-speech communication - this approach was supported in study by Rouseau et al highlighting the 'prevalence of smartphones, portable digital media players and the widespread us of short message service..may provide a readily accessible and cost-effective alternative communication option" for patients on temporary vocal restrictions following phonmicrosurgery (Rousseau 2015)

Clinical trials registered recruting patiens for evaluation of voice rest after phonosurgery: Home - ClinicalTrials.gov - search "voice rest"

References

Anderson TD: "Benign Lesions of the Larynx" Chapter 24 pp 303-322 in Textbook of Laryngology  Editors Albert L. Merati and Steven A Bielamowicz Plural Publishing San Diego 2007

ASHA - American Speech-Language-Hearing Association. Frequently Asked questions About Voice Therapy https://www.asha.org/slp/clinical/frequently-asked-questions-about-voice.... Accessed April 10, 2022.

Ballenger HC, Ballenger JJ: "Disease of the nose, throat and ear." pp 367-376 In: Chronic diseases of the larynx, 10th ed. Philadelphia: Lea and Febiger, 1957

Behlau M, Oliveira G. Vocal hygiene for the voice professional. Curr Opin Otolaryngol Head Neck Surg. 2009 Jun;17(3):149-54. doi: 10.1097/MOO.0b013e32832af105. PMID: 19342952.

Behrman A, Rutledge J, Hembree A, Sheridan S. Vocal hygiene education, voice production therapy, and the role of patient adherence: a treatment effectiveness study in women with phonotrauma. J Speech Lang Hear Res. 2008 Apr;51(2):350-66. doi: 10.1044/1092-4388(2008/026). PMID: 18367682.

Behrman A, Sulica L. Voice rest after microlaryngoscopy: current opinion and practice. Laryngoscope. 2003;113:2182-2186.

Behrman, A. (2006). Facilitating behavioral change in voice therapy: The relevance of motivational interviewing. American Journal of Speech-Language Pathology, 15, 215–225

Bloch CS, Gould WJ, Hirano M: Effect of voice therapy on contact granuloma of the vocal fold. Ann Otol 1981;90:48-52

Childs LF, Mau T. Combining Voice Rest and Steroids to Improve Diagnostic Clarity in Phonotraumatic Vocal Fold Injury. J Voice. 2020 Jul 9:S0892-1997(20)30227-7. doi: 10.1016/j.jvoice.2020.06.003. Epub ahead of print. PMID: 32654865.

Cho SH, Kim HT, Lee IJ, Kim MS, Park HJ. Influence of phonation on basement membrane zone recovery after phonomicrosurgery: a canine model. Ann Otol Rhinol Laryngol. 2000;109(7):658-666. doi:10.1177/000348940010900709

De Bodt M, Patteeuw T, Versele A. Temporal Variables in Voice Therapy. J Voice. 2015 Sep;29(5):611-7. doi: 10.1016/j.jvoice.2014.12.001. Epub 2015 Mar 17. PMID: 25795350.

Dhaliwal SS, Doyle PC, Failla S, Hawkins S, Fung K. Role of voice rest following laser resection of vocal fold lesions: A randomized controlled trial. Laryngoscope. 2020;130(7):1750-1755. doi:10.1002/lary.28287

Ford CN and Bless DM: "Adjunctive Measures for Optimal Phonsurgical Results: Medical and Other Supportive Measures" Chapter 13 pp225-230 in Phonosurgery Assessment and Surgical Management of Voice Disorders. Editors Charles N Ford and Diane M Bless 1991

Haben CM. Voice rest and phonotrauma in singers. Med Probl Perform Art. 2012;27(3):165-168.

Hapner E, Portone-Maira C, Johns MM 3rd. A study of voice therapy dropout. J Voice. 2009 May;23(3):337-40. doi: 10.1016/j.jvoice.2007.10.009. PMID: 18674882

Hoffman HT, Overholt EM, Karnell MP and McCulloch TM: "Granuloma Contact Ulcers and Other Posterior Lesions" Chapter 17 pp 204-223 in The Larynx Editors Robert H Ossoff, Stanley M Shapshay, gayle E. Woodson, and James L. Netterville. Lippincott Williams & Wilkins  Philadelphia

Holmberg E.B., Hillman R.E., Hammarberg B., et. al.: Efficacy of a behaviorally based voice therapy protocol for vocal nodules. J Voice 2001; 15: pp. 395-412.

Ishikawa K, Thibeault S. Voice rest versus exercise: a review of the literature. J Voice. 2010 Jul;24(4):379-87. doi: 10.1016/j.jvoice.2008.10.011. Epub 2009 Aug 5. PMID: 19660903; PMCID: PMC2925639.

Jackson C Contact ulcer of the larynx. Ann Otol Rhinol Laryngol 1928;37:227-238

Jackson C, Jackson CL. Contact ulcer of the larynx. Arch Otolaryngol 1935;22:1-15

Jiang J, Verdolini K, Aquino B, Ng J, Hanson D. Effects of dehydration on phonation in excised canine larynges. Ann Otol Rhinol Laryngol. 2000 Jun;109(6):568-75. doi: 10.1177/000348940010900607. PMID: 10855568.

Joshi A, Johns MM 3rd. Current practices for voice rest recommendations after phonomicrosurgery. Laryngoscope. 2018;128(5):1170-1175. doi:10.1002/lary.26979

Kaneko M, Hirano S. Voice rest after laryngeal surgery: what's the evidence?. Curr Opin Otolaryngol Head Neck Surg. 2017;25(6):459-463. doi:10.1097/MOO.0000000000000407

Kaneko M, Shiromoto O, Fujiu-Kurachi M, Kishimoto Y, Tateya I, Hirano S. Optimal Duration for Voice Rest After Vocal Fold Surgery: Randomized Controlled Clinical Study. J Voice. 2017;31(1):97-103. doi:10.1016/j.jvoice.2016.02.009

Khodeir MS, Hassan SM, El Shoubary AM, Saad MNA. Surgical and Nonsurgical Lines of Treatment of Reinke's Edema: A Systematic Literature Review. J Voice. 2021 May;35(3):502.e1-502.e11. doi: 10.1016/j.jvoice.2019.10.016. Epub 2019 Nov 21. PMID: 31761692.

King RE, Dailey SH, Thibeault SL. Role of Voice Therapy in Adherence to Voice Rest After Office-Based Vocal Fold Procedures. Am J Speech Lang Pathol. 2021 Nov 4;30(6):2542-2553. doi: 10.1044/2021_AJSLP-21-00082. Epub 2021 Sep 14. PMID: 34520225.

Kostyk BE, Rochet AP. Laryngeal airway resistance in teachers with vocal fatigue: a preliminary study. J Voice. 1998;12:287–299.

Koufmann JA, Blalock PD (1989) Is voice rest never indicated? J Voice 3:87–91

McCabe DJ, Titze IR. Chant therapy for treating vocal fatigue among public school teachers: a preliminary study. Am J Speech Lang Pathol. 2002;11: 356–369.

Misono, S., Banks, K., Gaillard, P., Goding, G. S., & Yueh, B. (2015). The clinical utility of vocal dosimetry for assessing voice rest. The Laryngoscope, 125(1), 171–176. https://doi.org/10.1002/ lary.24887

Moghtader M, Soltani M, Mehravar M et al (2020) The relationship between vocal fatigue index and voice handicap index in university professors with and without voice complaint. J Voice 34:809.e1-809.e5. https://doi.org/10.1016/j.jvoice.2019.01.010 

Nanjundeswaran C, Jacobson BH, Gartner-Schmidt J, Verdolini Abbott K (2015) Vocal fatigue index (VFI): development and validation. J Voice 29:433–440. https://doi.org/10.1016/j.jvoice. 2014.09.012

Narasimhan SV, Gowda B. Multiparametric analysis of voice following prolonged voice use and voice rest in teachers: evidence from discriminant analysis. Eur Arch Otorhinolaryngol. 2022 Mar;279(3):1397-1404. doi: 10.1007/s00405-021-07144-2. Epub 2021 Oct 22. PMID: 34686892.

Neely JL, Rosen C. Vocal fold hemorrhage associated with coumadin therapy in an opera singer. J Voice. 2000 Jun;14(2):272-7. doi: 10.1016/s0892-1997(00)80035-1. PMID: 10875579.
 
Welham NV, Maclagan MA. Vocal fatigue: current knowledge and future directions. J Voice. 2003 Mar;17(1):21-30. doi: 10.1016/s0892-1997(03)00033-x. PMID: 12705816.

Niebudek-Bogusz E., Sznuorowska-Przygocka B., Fiszer M., et. al.: The effectiveness of voice therapy for teachers with dysphonia. Folia Phon Logop 2008; 60: pp. 134-141.

Ohlsson A-C, Gustavsson I, Hofling K, Wahle U, Osterlind C and Iwarsson J: Voice Therapy Outcome: A comparison Between Imitation Model Voice Therapy and Verbal Insturctions Model Voice Therapy. Journal of Voice 2022 (article in press)

Patel RR, Bless DM, and Thibeault SL: Boot Camp: a Novel Intensive Approach to Voice Therapy  Journal of Voice Volume 25, Isssue 5, Sepember 2011 pages 562-569

Ramig LO, Verdolini K. Treatment efficacy: voice disorders. J Speech Lang Hear Res. 1998 Feb;41(1):S101-16. doi: 10.1044/jslhr.4101.s101. PMID: 9493749.

Rihkanen H, Geneid A. Voice rest and sick leave after phonosurgical procedures: surveys among European laryngologists and phoniatricians. Eur Arch Otorhinolaryngol. 2019 Feb;276(2):483-487. doi: 10.1007/s00405-019-05283-1. Epub 2019 Jan 10. PMID: 30631900; PMCID: PMC6394435.

Rousseau B, Gutmann ML, Mau T, Francis DO, Johnson JP, Novaleski CK, Vinson KN, Garrett CG. Randomized controlled trial of supplemental augmentative and alternative communication versus voice rest alone after phonomicrosurgery. Otolaryngol Head Neck Surg. 2015 Mar;152(3):494-500. doi: 10.1177/0194599814566601. Epub 2015 Jan 20. PMID: 25605690; PMCID: PMC4617180.

Rousseau, B., Cohen, S. M., Zeller, A. S., Scearce, L., Tritter, A. G., & Garrett, C. G. (2011). Compliance and quality of life in patients on prescribed voice rest. Otolaryngology—Head & Neck Surgery, 144(1), 104–107. https://doi.org/10.1177/ 0194599810390465

Royal College of Speech and Language Therapists. Position statement: speech and language therapists working with individuals with voice disorders. https://www.rcslt.org/wp-content/uploads/media/docs/clinical-guidance/vo... April 10, 2022.

Rubin AD and Sataloff RT: "General Principles of Microlaryngeal Surgery" Chapter 14 pp167-188 in Plural Publishing San Diego 2007

Sataloff RT and Spiegel JR: "Endoscopic Microsurgery" Chapter 12 pp227-267 in Voice Surgery Editors Wilbur James Gould, Robert Thayer Sataloff, and Joseph Richard Spiegel  Mosby-Year Book, Inc St Louis 1993

Scherer RC, Titze IR, Raphael BN, Wood RP, Ramig LA, Blager RF. Vocal fatigue in a trained and an untrained voice user. In: Baer T, Sasaki C, Harris K, eds. Laryngeal function in phonation and respiration. San Diego: Singular, 1991.  

Stachler RJ, Francis DO, Schwartz SR, et al. Clinical practice guideline: hoarseness (Dysphonia) (Update). Otolaryngol Head Neck Surg. 2018;158:S1–S42

Stemple JC, Stanley J, Lee L. Objective measures of voice production in normal subjects following prolonged voice use. J Voice. 1995;9:127–133

Stone RE: "The Speech-Language Pathologist's Role in the Management of the Professional Voice" pp 291-313 in Vocal Arts Medicine: The Care and Prevention of Professional Voice Disorders. Editors Michael S Benninger, Barbara H. Jacobson, and Alex F. Johnson Thieme Medical Publishers, Inc. New York 1994

Thomas, L. B., & Stemple, J. C. (2007). Voice therapy: Does science support the art? Communicative Disorders Review, 1, 51–79.

van der Merwe A. The voice use reduction program. Am J Speech Lang Pathol 2004; 13:208–218.

Vaughan CW and Gould WJ: "Management of Vocal Pathology in the Voice Professional" Chapter 19 pp 203-212 in The Larynx: A Multidisciplinary Approach  Editor Marvin Fried  Little, Brown and Co  Boston 1988

Watts CR, Hamilton A, Toles L, Childs L, Mau T. A randomized controlled trial of stretch-and-flow voice therapy for muscle tension dysphonia. Laryngoscope. 2015 Jun;125(6):1420-5. doi: 10.1002/lary.25155. Epub 2015 Jan 30. PMID: 25641591.

Welham NV and Maclagan MA: Vocal Fatigue: Current Knowledge and Future Directions  Jounal of Voice Vol. 17, No.1, pp21-30

Whitling S, Lyberg-Åhlander V, Rydell R. Absolute or relative voice rest after phonosurgery: a blind randomized prospective clinical trial. Logoped Phoniatr Vocol. 2018;43(4):143-154. doi:10.1080/14015439.2018.1504985

Woodson GE: Laryngitis Chater 12 pp 152-157 in The Larynx Editors Robert H. Ossoff, Stanley M Shapshay, Gayle E Woodson, and James L. Netterville  Lippincott Williams & Wilkins Philadelphia 2003