In this paper, the etiology, treatment and psychological and/or behavioral factors of vocal fold nodules in adults, children and professional singers are reviewed and some suggestions for treatment options summarized. One recommendation that persists in almost every case and in almost every article is that preventative care of the vocal folds and stress reduction are by far the most preferable ways in which to deal with vocal fold nodules. Given that people usually do not seek expert advice until some condition has already occurred, there are a variety of therapies, including hygiene, hydration, voice training, and surgery, as a last resort, to preserve the voice’s function, and these are all discussed below.
Vocal fold nodules are symmetric swelling of the bilateral epithelium of the anterior/mid-third of the true vocal folds. A vocal fold nodule is a benign growth, almost like a callus, in the middle on both vocal folds. It is normally the result of chronic vocal overuse or abuse. Vocal fold nodules often cause interference with the closure of vocal folds, and thus a common symptom is dysphonia. Typically, the subject will exhibit a hoarse voice, high effort to speak, and faster than usual vocal fatigue. (Muhammad, et al., 2011, 5-6).
Vocal fold nodules present differently among adults, children, and singers, though some of the causes of the condition may be similar, or even the same. Generally there is some prolonged abuse or overuse of the voice, in adults as a result of some personality trait, or occupation, or situation (Hedever, 2009, 5-6), in children as a consequence of ordinary childhood social interaction, often at the top of a child’s voice, or for childhood psychological traits or conditions (Roy, 2005, 157-158), and for professional singers, a variety of situations, from a concert tour with daily assault on the vocal apparatus, to prolonged studio production work and resulting overuse and pressure, to alcohol and smoke (Cain, 1998, 148-149). In each case, though, the etiology is generally related to the frequency of usage and the extent to which the usage exceeds physically safe boundaries. Nodules are generally not something that develops overnight and often represent prolonged harmful activity. For adults and professional singers, it is also not uncommon for etiology to include risk factors such as tobacco usage or so-called second-hand smoke, alcoholic consumption, medications that dry the larynx and vocal fold membranes, and personal and professional schedules which cause adults to adopt habits which do not include sufficient hydration to protect the vocal fold membranes. (Hedever, 2009, 6).
Generally, nodules arise where they do because the middle of the vocal folds is the focus of the most stress while producing sounds. Of course, there are other well-demonstrated factors that can contribute to the eruption of nodules, such as smoking, some medications that cause dryness, caffeine intake, certain allergies, prolonged gastric reflux, and even some contact with certain noxious chemicals or gases. (Hedever, 2009, 6; Chernobelsky, 2007, 178).
In the case of vocal nodules, there are a variety of treatments and therapies available depending on the nature and extent of the condition. Among the most common are voice hygiene intervention, such as hydration therapy, and in some cases, laryngopharyngeal reflux intervention, and voice production therapies. These may include Resonant Voice Therapy, Accent Method, and Confidential Voice Therapy. (Hedever, 2009, 22-33).
Vocal Hygiene Intervention involves teaching patients to keep their vocal fold tissue moist and irritant-free. It is the first line of defense to protect the vocal folds, and one of the first means of treating, among other things, mild nodule conditions. One of the simplest training techniques to relieve vocal fold stress, and treat nodules, is hydration therapy. Hydration therapy is effective because research shows that when the vocal folds are moist, they vibrate with the least amount of effort (sometimes referred to as “push” from the lungs) (Hedever, 2009, 22). Hydration therapy is not only preventative but has also been shown to be therapeutic in reversing existing conditions and injury. (Ibid).
By hydrating the vocal folds less power is required to drive them, allowing time for healing. Moist vocal folds also protect against injury and can reverse the effects of some injuries. Hydration therapy itself can include as many as three components, hydration of cells, direct application of vapor, and hydrating medications. (Hedever, 2009, 22).
Cell hydration therapy involves two cooperative efforts. First, in order to moisten the tissue and cells internally, patients are advised to drink sufficient water depending on physiology. Second, patients are cautioned to avoid consuming or coming in contact with substances or conditions (e.g. environmental conditions) that dry out the body, such as caffeine, alcohol, or diuretics not medically necessary. (Ibid).
Vapor or steam therapies can be applied as hydration treatments to moisten the surface of the vocal fold tissue. There are several simple methods that can be used without resort to any devices or external tools or materials. Sitting in a bathroom with the door closed and the shower running with hot water can produce sufficient steam. Note that this is somewhat convenient, but is somewhat less effective than direct steam/vapor therapies. (Ibid).
Direct steam therapy can be performed by placing the face over warm steam for at least several minutes at least a few times each day. Another form of direct steam therapy is the use of a hot water vaporizer. As with the hydration mentioned above, patients are cautioned to avoid all drying conditions, unless the product of medications indicated for medical reasons.
Another approach to hydrating vocal folds is to stimulate and use bodily secretions to keep them moist. Guaifenesin, an ingredient found in low concentrations in over the counter Robitussin, and in Humibid, a prescription medication, helps accomplish this. Only the simple form of Robitussin can be used as the other forms with additives all contain ingredients which cause drying, counterproductive to the hydration therapy. (Hedever, 2009, 24).
There is a class of vocal fold nodules that arise from laryngopharyngeal reflux (LPR), a condition whereby a spillover of acids from the esophagus into the larynx causes damage to vocal folds. There are a variety of options for treatment, including behavioral, medication and surgery. (Ibid).
The most conservative treatment is behavioral. Patients who experience reflux can moderate it by avoiding spicy foods, alcohol, caffeine, and fatty or oily and fried foods. Also helpful for moderating reflux discomfort is sleeping with the head elevated from the waist up to keep stomach acid from spilling into the larynx during the night. Also, as part of the behavioral treatment, patients are advised to avoid eating any food within four hours of sleeping, and for patients with extra weight around the waist, weight loss. Although these steps appear simple, actually modifying behavior is never simple, especially when it comes to avoiding certain lifelong favorite foods or challenging cultural beliefs. For these people, there is another alternative for dealing with acid resulting from eating certain foods. (Hedever, 2009, 24)
For many, one of the most popular acid reduction regimens today involves medication. There are different types of medication regimens, and different people may find one or more of them most efficient. First, there are H2 blockers, such as Tagamet, Zantac, Axid, or Pepcid, which block histamine, one of the elements involved in the formation of acid in the stomach. H2 blockers are not completely effective at blocking acid, however, and some patients might find it is insufficient to stop the acid reflux. It is possible to combine taking an H2 blocker with modifying the diet to achieve a better solution. (Ibid).
Aside from H2 blockers, there is another class of medication called proton pump inhibitors, such as omeprazole (Prilosec), lansoprazole (Prevacid), and rabeprazole (Aciphex), which actually block hydrogen ions which ordinarily facilitate the production of acid, thereby resulting in total suppression of stomach acid. (Hedever, 2009, 25).
Another class of drugs, “motility drugs”, such as cisapride (Propulsid) and metoclopramide (Reglan), helps develop esophageal sphincter muscle and increases the volume of gastric fluids emptied. The reduction in the volume of fluids can help provide comfort and prevent acid from flowing through the esophagus to the vocal folds. (Ibid).
Failing to achieve sufficient acid reduction, and with persistent cases, fundoplication surgery maybe be indicated. Here, a small incision is made in the navel, and the fundus is wrapped around the lower part of the esophagus, actually constructing a tighter sphincter to keep acid from entering the esophagus. (Hedever, 2009, 25).
In general, voice production techniques are methods used to train patients how to use their vocal mechanics to produce optimal sound while first reversing and then preventing further injury, or in some cases, disease. Here, we will examine those voice production techniques that can be used in the treatment and prevention of vocal fold nodules.
RVT can be used for patients suffering from vocal fold nodules. (Hedever, 2009, 29). Dr. Arthur Lessac developed an approach for RVT, improved on by Dr. Katherine Verdolini, that entails using utterances (generally “y” and nasal consonants “m”, “n” and “ng”) to produce the strongest output with the least amount of vocal fold impact. This method also reduces the degree of lung pressure needed to vibrate the vocal folds. This “resonant” voice seems to provide protection from further injury with little effort. (Hedever, 2009, 29).
One study has provided evidence that RVT may provide beneficial results for vocal fold nodules, though the sample in the study was limited to 13 adult females with nodules. Each participant received a combination of therapies of either RVT and vocal hygiene, or Confidential Voice Therapy (CVT) and vocal hygiene (see below). The control group received only vocal hygiene treatments. Those patients who were following their RVT or CVT therapies at home showed benefits from the treatments. Those who reported not following up with treatments at home reported no benefits. (Verdolini 1995, 84-85).
CVT involves the patient producing a quiet, easy, breathy voice, which provides small amplitudes of vibration in the vocal folds, preventing them from a forceful collision, protecting them from harm during a healing cycle. This method is generally called for where the damage to the vocal folds is recent or the patient has had vocal fold surgery. (Hedever, 2009, 32-33).
As mentioned above, a study performed using RVT or CVT in combination with Voice Hygiene Treatment produced successful results in treating vocal fold nodes. (Verdolini, 1995, 85).
The Accent Method is more commonly used outside the United States, where therapists acknowledge its success for most disorders, including reduction of the size of vocal fold nodules. (Kotby, 1991, 318). The therapy involves training patients to produce vocal sounds with simple, abdominal breathing and rhythmic swaying that produces relaxed vocal folds. According to Kotby, the method appears to succeed because it produces new motor patterns which are timed in a way that produces these optimal vocal fold vibrations, where the vocal folds hardly touch.
In addition to the physical factors which might affect the development of vocal fold nodules, there are psychological factors which can also allow their development as well. These include the relationship between personality and voice, aggressive personality, talkativeness, tenseness, and anger. Some of these characteristics might affect the voice through abuse or overuse, and some might create physiological conditions, such as tenseness, which can affect the vocal folds. (McHugh-Munier, 1997, 453). The emotional state of a person, their coping style, and the effects for that individual on the voice all contribute to the risk of developing nodules:
The relationship between emotional state, coping style, and voice is a complex one.....The emotional state is considered to have an effect on respiration and the muscle tension involved in phonation and articulation, which in turn modifies the acoustic parameters of the voice, depending on the emotion expressed. [T]hese physiological changes would affect the tension of the respiratory, phonatory, and articulatory musculature, resulting in differential changes in voice. (McHugh-Munier, 1997, 454).
The existence of these psychological factors suggests methods of treatment beyond the ordinary concentration on the vocal folds themselves, such as hygiene and hydration, or even voice control techniques, such as RVT and CVT. In the case of voice conditions attributed to or exacerbated by psychological factors, there may be calming therapy which could manage or ease the tension or the conditions under which the adverse voice style or affect contributes to the development of nodules. This could be especially effective for professionals who use their voice in their job, and especially so for singers, where high stress and pressure can create a kind of perfect storm for developing vocal fold nodules. (Ibid 454-455, 459).
The definition of pediatric voice fold nodules is the same as for adults. The etiology is somewhat different, though generically it is broadly understood to be overuse or abuse of the voice, but as discussed below, it appears there are some behavioral aspects to the development of the condition. It has been reported that vocal fold nodules constitute an estimated 24% of cases of larynx pathology in children. (Valdez, 2012, 1362).
In pediatric vocal fold nodule treatment, those methods mentioned herein for treating adult vocal fold nodules are applicable, in particular, vocal hygiene and hydration, aside from medication regimens, which are subject to different dosages, if used, and avoidance of certain substances, such as caffeine, which is more likely to come in soda for children than coffee, as in adults. As for the Accent Method, which is focused on behavior modification, recent developments have produced alternatives in methodology, such as the use of software programs to aid in pediatric resolutions such as those discussed by Valdez, et al. (2012). In Valdez, et al. (2012), the purpose of the study was to develop measurements of vocal parameters both before and after a particular IBM developed software facilitated voice therapy in children with vocal fold nodules, with measurements of the fundamental frequency, videonasolaryngoscopy data, shimmer and jitter, and voice assessment. The study included 20 patients aged 6 to 10, 15 males and 5 females, with nodules ranging in size from 1 to 4 mm. (Ibid), and the 20 patients not in the control group received voice therapy. Patients received voice therapy sessions twice a week, 45 minutes for each session Voice therapy consisted of sessions using the Speech Viewer III (SV-III-IBM) software.
“The software provided visual support of the acoustic parameters during voice therapy. All patients were subjected to the same therapy protocol, including voice presence and awareness, phonation duration, and vocal attack. Each item was practiced for 10 min for a total time of 30 min per session. The remaining 15 min of each session were used for talking to the family about…the voice problem and basic vocal hygiene education. The therapy basically provided behavioral modification to train the children to produce a target voice. The children and their families were assigned outside activities to reinforce the behavioral modification. The therapy lasted 20 weeks, 40 sessions in all.” (1362-63).
The Speech Viewer software appears to have been quite useful in treating vocal fold nodules in children (and the software indicates that it is rated for adults as well), and because of its “fun” aspect, it was a somewhat preferable tool. However, as with most software, at some point it became outmoded, and the producers have not upgraded the program since 1997, and indications are it will not be upgraded. There are systems in existence that have similar features and success, such as Visi-Pitch IV, used by speech therapists in particular for pediatric cases, though this program can be used by adults as well. (Campisi, et al., 2002, 156-157).
In pediatric cases of vocal fold nodules, some psychological and behavioral effects may be observed. The development of vocal fold nodules in children has been attributed to certain aggressive or social behavior and yelling, screaming, speaking loudly for prolonged periods.
as in the 5-year St. Louis County School study of 33,000 children (Roy, et al., 2005, 158) which catalogued certain traits such as talkativeness (up to three times as much as their peers), and concluded children with voice problems were more difficult to manage, “more vocally aggressive, more hypochondriacal, and had a greater tendency toward repressed physical aggression.” (Ibid). Although these conclusions corresponded to many similar findings in this area, Roy, et al. (2005) indicated that “much of the early literature…was based on clinical observations/assertions, non-standardized procedures, or projections techniques with questionable psychometric properties.” (Ibid). In Roy, et al, (2005) where the study used a more formal design (but the sample was 65 children, 27 with vocal fold nodules, far fewer than St. Louis study), the conclusion was that “on the whole, no significant differences were detected between the groups; however the [vocal fold nodule] group scored significantly higher than the controls on the “Social Scale…” Also, the paper noted that several items, such as “screams a lot” and “teases a lot” approached significant differences, and “in adults with [vocal fold nodules] there is an apparent relationship between specific personality traits and the development of [vocal fold nodules.” (Ibid 166).
As seen with adults and children, the development of vocal fold nodules arises from overuse or abuse of the voice. No profession likely fits the conditions for overuse or abuse more than professional singing. The more popular the singer, the more often they sing, and the more often they sing, the more abuse or overuse. In addition, the nature of singing itself is not like speaking too loud or even yelling, which occurs in spurts. Professional singers are straining their voice almost always whenever they are singing. Not all singers develop the condition, so physiologically there are differences among the way vocal folds function in different singers, and unique characteristics might lead to the condition in one singer but not in another. It is also likely that the nature of the type of singing done has something to do with the extent of the risk of developing the condition. (Chernobelsky, 2007, 178-179; Cain, 1998, 1-5).
Moreover, there are other factors which also could contribute to vocal fold nodules, as mentioned before, such as alcohol, tobacco, caffeine, or from psychological or emotional conditions, such as stress, or pressure from others (such as agents, teachers, other professionals). (Cain, 1998, 2).
Although Chernobelsky did research for his study in Russia for 24 years, the sample was relatively small and included one male and 27 females. His conclusion essentially is that vocal fold nodules come back in all cases and that no therapy is permanent, including microsurgery. His recommendation that music colleges deny admission to any applicants with vocal fold nodules might be considered extreme, in particular considering dedication by many professional singers to their craft, and success despite the development of the condition. (Ibid 183).
Singers with vocal fold nodules pose particularly difficult treatment challenges because they are most often unwilling to undergo any kind of surgery for fear of damage to the instrument through which their livelihood proceeds. In addition, professional singers, while probably living every day under conditions for developing vocal fold nodules, are also subjected to psychological factors as well, including stress, aggressive behavior, and talkativeness, as well as the physiological effects of tension. Most research concurs that the best treatment for any singer is prevention. If training early on for professional singers can be introduced for hydration, hygiene, and calming exercises, there is a better chance of preventing the development of vocal fold nodules in the first place. (Chernobelsky, 2007, 182-183; Cain, 1998, 148-150, 158-162)
We have examined the etiology, treatment, and psychological aspects of vocal fold nodules for adults, children and professional singers, and it appears from the literature that while there are some universal truths regarding all of the groups, such as hygiene and hydration, and some personality traits affecting incidence of the condition, there are different factors affecting these groups as a result of the different conditions under which they operate, and the traits unique to each group. It also is apparent from the literature that programs can be developed for members of each of these groups at risk, to train them to preserve their vocal health with simple daily procedures, such as good vocal fold hygiene, good hydration, and learning how to deal with stress (e.g. yoga, calming techniques) which, if learned early, can produce excellent results.
Cain, B.A. 1998. Vocal Abuse in Singers: Cause, Prevention, Remedies and Cures. Northwestern University, Evanston, Illinois. UMI Number: 9826736.
Campisi, P., Tewfik, T.L., Manoukian, J.J., Schloss, M.D., Pelland-Blais, E., Sadeghi, N. 2002. Computer-Assisted Voice Analysis: Establishing a Pediatric Database. Arch Otolaryngol Head and Neck Surgery. Vol. 128.156-160. Retrieved from http://stuyresearch.googlecode.com /hg/justice/research/456a156.pdf
Chernobelsky, S.I. 2007. The treatment and results of voice therapy amongst professional classical singers with vocal fold nodules. Logopedics Phoniatrics Vocology. 32: 178-184.
Hedever, Dr. Mladen. 2009. Vocology Guide. Zagreb: Tara Centar. Retrieved from http://www.taracentar.hr/attachments/vocology_guide.pdf
Kotby, M., El-Sady, S., Basiouny, S., Abou-Rass, Y., & Hegazi, M. (1991). Efficacy of the accent method of voice therapy. Journal of Voice, 5, 316-320.
McHugh-Munier, C., Scherer, K.R., Lehmann, W., Scherer, U.. 1997. Coping Strategies, Personality, and Voice Quality in Patients with Vocal Fold Nodules and Polyps. Journal of Voice. Vol. 11, No. 4. 452-461.
Muhammad et al. (2011)’ Formant analysis in dysphonic patients and automatic Arabic digit speech recognition”. BioMedical Engineering OnLine 10, 41
Roy, N., Holt, K.I., Redmond, S, Muntz, H. 2005. Behavioral characteristics of children with vocal fold nodules. Journal of Voice, 21(2) 157-168.
Valadez,V., Ysunza, A.. Ocharan-Hernandez; Garrido-Bustamante, E., Araceli, N., Sanchez-Valerio, M. & Pamplona, C. (2012). Voice parameters and videonasolaryngoscopy in children with vocal nodules: A longitudinal study, before and after voice therapy. International Journal of Pediatric Otorhinolaryngology 76 (2012). 1361–1365.
Verdolini-Marston, K., Burke, M.K., Lessac, A., Glaze, L., & Caldwell, E. (1995). “A preliminary study on two methods of treatment for laryngeal nodules”. Journal of Voice, 9, 74-85.