The Efficacy of Lax Vox Voice Therapy in Patients with Sulcus Vocalis

Fenise Selin Karalı Hava Çetin

Introduction: Sulcus Vocalis, which is usually bilaterally symmetrical, is a furrow running parallel to the free side of vocal folds. The cause of this disorder is not widely studied and its etiology is poorly understood. The three main causes for sulcus vocalis that are reported in the literature are congenital, acquired and unknown causes. When it comes to the management of Sulcus vocalis, one of them is medical interventions (e.i. surgery) and the other one is non-medical methods such as voice therapy, vocal hygiene and behavior modifications. Aim: Lax Vox is a holistic therapy approach for various functional and organic voice disorders. As it aims to change the whole mechanism of voice, all of the vocal pathways are used simultaneously and without force.  In this study, it was aimed to determine the efficacy of Lax Vox Voice Therapy in two patients with Sulcus Vocalis. Method: Both patients had undergone therapy sessions for 7 weeks. With the Lax Vox Therapy tool, patients were asked to do bubbling without phonation, sostenuto, stacato and portemento exercises at their own pace. All of the exercises were repeated six times a day between therapy sessions. With the help of these exercises, it was aimed to expand the voice range in different pitches. During the therapy sessions, patients were also expected to follow vocal hygiene recommendations. Instrumental and perceptive evaluations were performed pre-therapy and post-therapy. Findings: As a result of the therapy, it was found that the vocal folds had better adduction; maximum phonation time was increased and also, s/z ratio was significantly better. In the first patient, Lax Vox therapy was more effective than the second patient. Maximum phonation time in the second patient was longer after therapy, but it was not significant as in the first patient. Although Lax Vox Voice therapy was found effective in both patients, one of them has gained more from therapy sessions. This can be explained by personal motivation and repeating exercises regularly during the therapy process. Results and discussion: As a result of this study, voice therapy was found effective in improving voice quality in two patients with Sulcus Vocalis. Due to its holistic approach, Lax Vox Therapy targets all of the phonatory system and provide coordination without force. With the help of the Lax Vox Voice therapy tool, the biomechanical and physical process of the phonatory apparatus can change and it helps patients to produce voice with minimum effort. As there are not enough studies, more research is needed to determine the efficacy of Lax Vox in Sulcus Vocalis.


Lax vox, sulcus vocalis, voice therapy, voice, vocal folds


Boone, D. R., McFarlane, S. C., Von Berly, S. L., & Zraick, R. I. (2010). The Voice and Voice Therapy. (8. bsk). Boston, MA: Pearson Publication.

Bouchayer, M., Cornut, G., Loire, R., Witzig, E., Roch, J. B. & Bastian, R. (1985) Epidermoid cyst, sulci, and mucosal bridges of the true vocal cord: a report of 157 cases. Laryngoscope, 95(9), 1087–1094.

Damrose, E. J. & Berke, G. S. (2003). Advances in the management of glottic insufficiency. Otolaryngology Head and Neck Surgery. 11, 480-484.

Denizoğlu, İ. (2013). Lax Vox ses terapisinde yöntem ve uygulamalar. Türkiye Klinikleri Journal of Ear Nose Troath-Special Topics, 6(2), 32-40.

Friedrich, G., Dikkers, F. G. & Arens, C. (2013) Vocal fold scars: current concepts and future directions. Consensus report of the phonosurgery committee of the European Laryngological Society. European Archives of Otorhinolaryngoly 270, 2491–2507.

Ford, C. N., Inagi, K., Khidr, A., Bless, D. M., & Gilchrist, K. W. (1996). Sulcus vocalis: A rational analytical approach to diagnosis and management. Annals of Otology, Rhinology & Laryngology, 105(3), 189–200.

Giovanni, A., Chanteret, C. & Lagier, A., (2007) Sulcus vocalis: A review. European Archives of Otorhinolaryngology, 264, 337–344.

Husain, S. & Sulica, L. (2016) Familial sulcus vergeture: further evidence for origin of type 2 sulcus. Journal of Voice, 30(6), 761.e19–761.e21.

Mailänder, E., Mühre, L., & Barsties, B. (2017). Lax Vox as a voice training program for teachers: A pilot study. Journal of voice, 31(2), 262-e13.

Mendes, A. L. F., do Carmo, R. D., de Araújo, A. M. G. D., Paranhos, L. R., da Mota, C. S. O., Schneiberg, S., ... & Aragão, J. A. (2018). The effects of phonation into glass, plastic, and laxvox tubes in singers: a systematic review. Journal of Voice.Miaśkiewicz. B.& Szkiełkowska, A. (2015) Diagnostic difficulties in sulcus vocalis. Nowa Audiofonologia 4(1), 60–63.

Nakayama, M., Ford, C. N., Brandenburg, J. H. & Bless, D. M. (1994) Sulcus vocalis in laryngeal cancer: A histopathologic study. Laryngoscope 104, 16–24.

Pontes, P., & Behlau, M. (1993) Treatment of sulcus vocalis: auditory perceptual and acoustical analysis of the slicing mucosa surgical technique. Journal of Voice, 7, 365-376.

Rajasudhakar, R. (2016). Effect of voice therapy in sulcus vocalis: A single case study. South African Journal of Communication Disordes, 63(1), a146.

Romero-Arias, T., García-Escudero, F., Redondo-Ventura, F. & Betancort-Montesinos, M. (2018). Acoustic analysis and speech therapy intervention in spoken and sung voice with the Lax Vox technique: on the subject of a case. Majorensis, 14, 49-56.

Rubin, J.S., & Yanagisawa, E. (2006). Benign vocal fold pathology through the eyes of the laryngologist. J. S. Rubin, R. T Sataloff, & G. S. Korovin (Ed.) içinde, Diagnosis And Treatment of voice Disorders. (3. Bsk), sf. 209–221). San Diego, CA: Plural Publishing Inc.