Articles

Effects of Occupational Vocal Demand on Subjective Vocal Symptoms and Acoustic Indicators of Laryngeal Tension in Speech-Language Pathologists

AUTHOR
Jaeock Kim, Ji Hang Jung
INFORMATION
2026, Vol. 11, Issue 1 / pp. 57-68
e-ISSN
2508-5948
p-ISSN

ABSTRACT

Purpose Speech-language pathologists (SLPs) are professional voice users whose clinical duties place sustained phonatory demands on the laryngeal system throughout their workdays. However, field-based evidence on the effects of routine clinical work on vocal symptoms and laryngeal tension remains limited. This study examined pre- to post-shift changes in subjective vocal symptoms and acoustic measures associated with laryngeal tension in SLPs. Methods Twenty-seven female SLPs completed ratings for vocal effort (adapted Borg CR-10 scale), vocal fatigue, and laryngeal discomfort (5-point Likert scale) before and immediately after their work shifts. Smartphone-based voice samples were collected on-site. Fundamental frequency (F0), intensity (I), relative fundamental frequency (RFF; offset 10 and onset 1), cepstral peak prominence (CPP), CPP standard deviation (CPP SD), low-to-high spectral ratio (L/H ratio), and L/H ratio standard deviation (L/H ratio SD) were extracted and compared using paired t tests. Results All three subjective symptom ratings increased significantly after work. Among acoustic measures, F0, I, and L/H ratio increased significantly, whereas RFF offset 10 decreased significantly. No significant pre- to post-shift differences were observed in RFF onset 1, CPP, CPP SD, or L/H ratio SD. Conclusions Routine clinical work was associated with worsening vocal symptoms and acoustic changes consistent with increased laryngeal tension in SLPs. These findings underscore the importance of preventive voice care, structured recovery periods, and practical self-management strategies for SLPs exposed to high occupational vocal demands.

Keyword
speech-language pathologists vocal demand vocal effort relative fundamental frequency laryngeal tension

REFERENCES

  1. Fujiki RB, Huber JE, Sivasankar MP. The effects of vocal exertion on lung volume measurements and acoustics in speakers reporting high and low vocal fatigue. PLoS One. 2022;17(5):e0268324. https://doi.org/10.1371/journal.pone.0268324 [Crossref] [Pubmed] [ETC]
  2. Hunter E, Cantor-Cutiva L, van Leer E, van Mersbergen M, Nanjundeswaran C, Bottalico P, Sandage MJ, Whitling S. Toward a consensus description of vocal effort, vocal load, vocal loading, and vocal fatigue. J Speech Lang Hear Res. 2020;63(2):509-32. https://doi.org/10.1044/2019_JSLHR-19-00057 [Crossref] [Pubmed] [ETC]
  3. Chan RW. Ovine vocal fold tissue fatigue response to accumulated, large-amplitude vibration exposure at phonatory frequencies. J Speech Lang Hear Res. 2019;62(12): 4291-9. https://doi.org/10.1044/2019_JSLHR-S-19-0181 [Crossref] [Pubmed] [ETC]
  4. Solomon NP. Vocal fatigue and its relation to vocal hyperfunction. Int J Speech Lang Pathol. 2008;10(4): 254-66. https://doi.org/10.1080/14417040701730990 [Crossref] [Pubmed]
  5. Kim JS, Choi SH. Voice problems and self-care practice for vocal health: current status of Korean speech-language pathologists. Commun Sci Disord. 2018;23(2): 414-24. https://doi.org/10.12963/csd.18498 [Crossref]
  6. Remacle A, Morsomme D, Finck C. Comparison of vocal loading parameters in kindergarten and elementary school teachers. J Speech Lang Hear Res. 2014;57(2): 406-15. https://doi.org/10.1044/2013_JSLHR-S-12-0351 [Crossref] [Pubmed]
  7. Bottalico P, Graetzer S, Hunter EJ. Effects of speech style, room acoustics, and vocal fatigue on vocal effort. J Acoust Soc Am. 2016;139(5):2870-9. https://doi.org/10.1121/1.4950812 [Crossref] [Pubmed] [ETC]
  8. Jung JH, Kim JO. Comparison of remote-audiovisual teaching and face-to-face teaching on factors causing teachers' voice problems and subjective voice evaluation. Commun Sci Disord. 2023;28(2):327-39. https://doi.org/10.12963/csd.23956 [Crossref]
  9. Rantala LM, Hakala S, Holmqvist S, Sala E. Classroom noise and teachers' voice production. J Speech Lang Hear Res. 2015;58(5):1397-406. https://doi.org/10.1044/2015_JSLHR-S-14-0248 [Crossref] [Pubmed]
  10. Rosenthal AL, Lowell SY, Colton RH. Aerodynamic and acoustic features of vocal effort. J Voice. 2014;28(2): 144-53. https://doi.org/10.1016/j.jvoice.2013.09.007 [Crossref] [Pubmed]
  11. Hillman RE, Stepp CE, Van Stan JH, Zañartu M, Mehta DD. An updated theoretical framework for vocal hyperfunction. Am J Speech Lang Pathol. 2020;29(4):2254-60. https://doi.org/10.1044/2020_AJSLP-20-00104 [Crossref] [Pubmed] [ETC]
  12. McCabe DJ, Titze IR. Chant therapy for treating vocal fatigue among public school teachers. Am J Speech Lang Pathol. 2002;11(4):356-69. https://doi.org/10.1044/1058-0360(2002/040) [Crossref]
  13. McKenna VS, Stepp CE. The relationship between acoustical and perceptual measures of vocal effort. J Acoust Soc Am. 2018;144(3):1643-58. https://doi.org/10.1121/1.5055234 [Crossref] [Pubmed] [ETC]
  14. McKenna VS, Diaz-Cadiz ME, Shembel AC, Enos NM, Stepp CE. The relationship between physiological mechanisms and the self-perception of vocal effort. J Speech Lang Hear Res. 2019;62(4):815-34. https://doi.org/10.1044/2018_JSLHR-S-18-0205 [Crossref] [Pubmed] [ETC]
  15. Van Stan JH, Mehta DD, Ortiz AJ, Burns JA, Toles LE, Marks KL, Vangel M, Hron T, Zietels S, Hillman RE. Differences in weeklong ambulatory vocal behavior between female patients with phonotraumatic lesions and matched controls. J Speech Lang Hear Res. 2020;63(2): 372-84. https://doi.org/10.1044/2019_JSLHR-19-00065 [Crossref] [Pubmed] [ETC]
  16. Fujiki RB, Sivasankar MP. A review of vocal loading tasks in the voice literature. J Voice. 2017;31(3):388.e33-9. https://doi.org/10.1016/j.jvoice.2016.09.019 [Crossref] [Pubmed]
  17. Buekers R. Are voice endurance tests able to assess vocal fatigue? Clin Otolaryngol. 1998;23(6):533-8. https://doi.org/10.1046/j.1365-2273.1998.2360533.x [Crossref] [Pubmed]
  18. Lehto L, Laaksonen L, Vilkman E, Alku P. Changes in objective acoustic measurements and subjective voice complaints in call center customer-service advisors during one working day. J Voice. 2008;22(2):164-77. https://doi.org/10.1016/j.jvoice.2006.08.010 [Crossref] [Pubmed]
  19. Pierce J, Tanner K, Merrill R, Shnowske L, Roy N. A field-based approach to establish normative acoustic data for healthy female voices. J Speech Lang Hear Res. 2021;64(3):691-706. https://doi.org/10.1044/2020_JSLHR-20-00490 [Crossref] [Pubmed]
  20. Remacle A, Finck C, Roche A, Morsomme D. Vocal impact of a prolonged reading task at two intensity levels: objective measurements and subjective self-ratings. J Voice. 2012;26(4):e177-86. https://doi.org/10.1016/j.jvoice.2011.07.016 [Crossref] [Pubmed]
  21. Rantala L, Vilkman E, Bloigu R. Voice changes during work: subjective complaints and objective measurements for female primary and secondary schoolteachers. J Voice. 2002;16(3):344-55. https://doi.org/10.1016/S0892-1997(02)00106-6 [Crossref] [Pubmed]
  22. Jannetts S, Schaeffler F, Beck J, Cowen S. Assessing voice health using smartphones: bias and random error of acoustic voice parameters captured by different smartphone types. Int J Lang Commun Disord. 2019;54(2): 292-305. https://doi.org/10.1111/1460-6984.12457 [Crossref] [Pubmed]
  23. Lee SJ, Lee KY, Choi HS. Clinical usefulness of voice ecordings using a smartphone as a screening tool for voice disorders. Commun Sci Disord. 2018;23(4):1065-77. https://doi.org/10.12963/csd.18540 [Crossref]
  24. Latoszek BBV, Maryn Y, Gerrits E, De Bodt M. The Acoustic Breathiness Index (ABI): a multivariate acoustic model for breathiness. J Voice. 2017;31(4):511.e1-27. https://doi.org/10.1016/j.jvoice.2016.11.017 [Crossref] [Pubmed] [ETC]
  25. Kapsner-Smith MR, Díaz-Cádiz ME, Vojtech JM, Buckley DP, Mehta DD, Hillman RE, Tracy LF, Noordzij JP, Eadie TL, Stepp CE. Clinical cutoff scores for acoustic indices of vocal hyperfunction that combine relative fundamental frequency and cepstral peak prominence. J Speech Lang Hear Res. 2022;65(4):1349-69. https://doi.org/10.1044/2021_JSLHR-21-00466 [Crossref] [Pubmed] [ETC]
  26. Van Stan JH, Ortiz AJ, Cortes JP, Marks KL, Toles LE, Mehta DD, Burns JA, Hron T, Stadelman-Cohen T, Krusemark C, Muise J, Fox-Galalis AB, Nudelman C, Zeitels S, Hillman RE. Differences in daily voice use measures between female patients with nonphonotraumatic vocal hyperfunction and matched controls. J Speech Lang Hear Res. 2021;64(5):1457-70. https://doi.org/10.1044/2021_JSLHR-20-00538 [Crossref] [Pubmed] [ETC]
  27. Kim J, Jung JH. Relative fundamental frequency of female speakers by Korean consonant types. Commun Sci Disord. 2025;30(4):785-94. https://doi.org/10.12963/csd.250152 [Crossref]
  28. Park Y, Cádiz MD, Nagle KF, Stepp CE. Perceptual and acoustic assessment of strain using synthetically modified voice samples. J Speech Lang Hear Res. 2020; 63(12):3897-908. https://doi.org/10.1044/2020_JSLHR-20-00294 [Crossref] [Pubmed] [ETC]
  29. de Oliveira Lemos I, Picanço Marchand DL, Oliveira Cunha E, Alves Silvério KC, Cassol M. What are the symptoms that characterize the clinical condition of vocal fatigue? A scoping review and meta-analysis. J Voice. 2023;39(3):844.e1-18. https://doi.org/10.1016/j.jvoice.2022.12.018 [Crossref] [Pubmed]
  30. Faul F, Erdfelder E, Lang AG, Buchner A. G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007;39(2):175-91. https://doi.org/10.3758/BF03193146 [Crossref] [Pubmed]
  31. Ford Baldner E, Doll E, van Mersbergen MR. A review of measures of vocal effort with a preliminary study on the establishment of a vocal effort measure. J Voice. 2015;29(5):530-41. https://doi.org/10.1016/j.jvoice.2014.08.017 [Crossref] [Pubmed]
  32. Kim H. Neurologic speech-language disorders. Seoul: Sigmapress; 2012.
  33. McKenna VS, Vojtech JM, Previtera M, Kendall CL, Carraro KE. A scoping literature review of relative fundamental frequency (RFF) in individuals with and without voice disorders. Appl Sci. 2022;12(16):8121-39. https://doi.org/10.3390/app12168121 [Crossref]
  34. Lien Y-AS, Gattuccio CI, Stepp CE. Effects of phonetic context on relative fundamental frequency. J Speech Lang Hear Res. 2014;57(4):1259-67. https://doi.org/10.1044/2014_JSLHR-S-13-0158 [Crossref] [Pubmed] [ETC]
  35. Maryn Y, Corthals P, Van Cauwenberge P, Roy N, De Bodt M. Toward improved ecological validity in the acoustic measurement of overall voice quality: combining continuous speech and sustained vowels. J Voice. 2010;24(5):540-55. https://doi.org/10.1016/j.jvoice.2008.12.014 [Crossref] [Pubmed]
  36. Gerratt BR, Kreiman J, Garellek M. Comparing measures of voice quality from sustained phonation and continuous speech. J Speech Lang Hear Res. 2016;59(5): 994-1001. https://doi.org/10.1044/2016_JSLHR-S-15-0307 [Crossref] [Pubmed] [ETC]
  37. Stepp CE, Hillman RE, Heaton JT. The impact of vocal hyperfunction on relative fundamental frequency during voicing offset and onset. J Speech Lang Hear Res. 2010;53(5):1220-6. https://doi.org/10.1044/1092-4388(2010/09-0234) [Crossref] [Pubmed]
  38. Hunter EJ, Berardi ML, van Mersbergen M. Relationship between tasked vocal effort levels and measures of vocal intensity. J Speech Lang Hear Res. 2021;64(6):1829-40. https://doi.org/10.1044/2021_JSLHR-20-00465 [Crossref] [Pubmed] [ETC]
  39. Nam DH, Baek JY, Kim JO, Park SY, Choi HS. Changes in aerodynamic function and closed quotient with variable pitch and loudness in male classical singers. Speech Sci. 2007;14(2):23-33.
  40. Titze IR. On the relation between subglottal pressure and fundamental frequency in phonation. J Acoust Soc Am. 1989;85(2):901-6. https://doi.org/10.1121/1.397562 [Crossref] [Pubmed]
  41. Lien YA, Michener CM, Eadie TL, Stepp CE. Individual monitoring of vocal effort with relative fundamental frequency: relationships with aerodynamics and listener perception. J Speech Lang Hear Res. 2015;58(3):566-75. https://doi.org/10.1044/2015_JSLHR-S-14-0194 [Crossref] [Pubmed] [ETC]
  42. McKenna VS, Heller Murray ESH, Lien YAS, Stepp CE. The relationship between relative fundamental frequency and a kinematic estimate of laryngeal stiffness in healthy adults. J Speech Lang Hear Res. 2016;59(6): 1283-94. https://doi.org/10.1044/2016_JSLHR-S-15-0406 [Crossref] [Pubmed] [ETC]
  43. Serry MA, Stepp CE, Peterson SD. Physics of phonation offset: toward understanding relative fundamental frequency observations. J Acoust Soc Am. 2021;149(5): 3654-64. https://doi.org/10.1121/10.0005006 [Crossref] [Pubmed] [ETC]
  44. Heller Murray ES, Lien YS, Van Stan JH, Mehta DD, Hillman RE, Noordzij JP, Stepp CE. Relative fundamental frequency distinguishes between phonotraumatic and non-phonotraumatic vocal hyperfunction. J Speech Lang Hear Res. 2017;60(6):1507-15. https://doi.org/10.1044/2016_JSLHR-S-16-0262 [Crossref] [Pubmed] [ETC]
  45. Park Y, Stepp CE. Test-retest reliability of relative fundamental frequency and conventional acoustic, aerodynamic, and perceptual measures of individuals with healthy voices. J Speech Lang Hear Res. 2019;62(6): 1707-18. https://doi.org/10.1044/2019_JSLHR-S-18-0507 [Crossref] [Pubmed] [ETC]
  46. Aaron AS, Dragicevic DA, Toglia D, Estrada A, Stepp CE. Voice outcomes of clear speech cueing in individuals with Parkinson's disease. J Voice. 2025;S0892- 1997(25)00497-7. https://doi.org/10.1016/j.jvoice.2025.11.020 [Crossref] [Pubmed]
  47. Smith AG, Sandage MJ, Pascoe DD, Plexico LW, Lima IR, Cao G. Elementary school teachers' vocal dose: muscle bioenergetics and training implications. J Speech Lang Hear Res. 2017;60(7):1831-42. https://doi.org/10.1044/2016_JSLHR-S-16-0193 [Crossref] [Pubmed]
  48. Whitling S, Rydell R, Lyberg-Åhlander V. Design of a clinical vocal loading test with long-time measurement of voice. J Voice. 2015;29(2):261.e13-27. https://doi.org/10.1016/j.jvoice.2014.07.012 [Crossref] [Pubmed]
  49. Hunter E, Titze I. Quantifying vocal fatigue recovery: dynamic vocal recovery trajectories after a vocal loading exercise. Ann Otol Rhinol Laryngol. 2009;118(6):449-60. https://doi.org/10.1177/000348940911800608 [Crossref] [Pubmed] [ETC]
  50. Whitling S, Lyberg-Åhlander V, Rydell R. Recovery from heavy vocal loading in women with different degrees of functional voice problems. J Voice. 2017;31(5):645.e1-14. https://doi.org/10.1016/j.jvoice.2016.12.012 [Crossref] [Pubmed]
  51. Toles LE, Ortiz AJ, Marks KL, Burns JA, Hron T, Van Stan JH, Mehta DD, Hilman RE. Differences between female singers with phonotrauma and vocally healthy matched controls in singing and speaking voice use during 1 week of ambulatory monitoring. Am J Speech Lang Pathol. 2021;30(1):199-209. https://doi.org/10.1044/2020_AJSLP-20-00227 [Crossref] [Pubmed] [ETC]
  52. Fujiki RB, Huber JE, Sivasankar MP. Restoration strategies following short-term vocal exertion in healthy young adults. J Speech Lang Hear Res. 2021;64(7): 2472-89. https://doi.org/10.1044/2021_JSLHR-20-00713 [Crossref] [Pubmed] [ETC]
  53. Kang J, Xue C, Lou Z, Scholp A, Zhang Y, Jiang J. The therapeutic effects of straw phonation on vocal fatigue. Laryngoscope. 2020;130(11):E674-9. https://doi.org/10.1002/lary.28498 [Crossref]
  54. Verdolini Abbott K, Li N, Branski R, Rosen C, Grillo E, Steinhauer K, Hebda PA. Vocal exercise may attenuate acute vocal fold inflammation. J Voice. 2012;26(6): 814.e1-13. https://doi.org/10.1016/j.jvoice.2012.03.008 [Crossref] [Pubmed] [ETC]
  55. Shin WS, Lee SJ. Comparison of voice improvement effects from semi-occluded vocal tract exercises and voice rest between treatment sessions among speech-language pathologists. Commun Sci Disord. 2025;30(1):192-205. https://doi.org/10.12963/csd.250092 [Crossref]
  56. Remacle A, Garnier M, Gerber S, David C, Petillon C. Vocal change patterns during a teaching day: inter- and intra-subject variability. J Voice. 2018;32(1):57-63. https://doi.org/10.1016/j.jvoice.2017.03.008 [Crossref] [Pubmed]