Voice production Larynx and the vocal folds ARTICULATION PHONATION - PDF document

M Södersten, Karolinska Institutet, Rekjavik, Oct 12, 2012 ”Voice team” Karolinska University Hospital and Karolinska Institute Voice production and teachers’ voice disorders How does the voice work and what makes it to fail? Södersten Maria Speech therapist, PhD, Associate prpfessor KTH 1 Speech Language Pathology, Karolinska university Hospital Speech language pathologists 2 Division of Speech Pathology, Clintec, Karolinska Institutet ENT/phoniatricians Engineer Reykjavik October 12 2012 2 Voice production Larynx and the vocal folds ARTICULATION PHONATION BREATHING (Lena Lyons efter CIBA, The larynx) Sundberg, 2001 Structure of a vocal fold Demonstration Epithelium Superficial layer Intermediate layer Lamina propria Deep layer Muscle Vocalis GOOD FOR VIBRATIONS Hirano et al, 1983 1

M Södersten, Karolinska Institutet, Rekjavik, Oct 12, 2012 Too much voice use may cause: How fast do the vocal folds vibrate ? Women Men � Damage to the Vocal fold vibrations/sec (Hz) 200 100 lamina propria due to mechanical forces Total amount of vibrations 1 minute 12 000 6000 � Fatigue in the Vocalis muscle Teachers vocal fold vibrate ca 20-30 % during work 1-2 miljon vibrations / working day e.g., Chang Karnell 2004; Titze 1994; Hunter, Titze 2009; 2010; Lyberg Åhlander, 2011; Morrow, Connor 2010; Rantala, Vilkman 1999; Titze m fl 2007) Voice activity and voice rest Teachers and pre-school teachers Hypothesis: The more loading the longer recovery is needed. Important with voice rest and pauses for teachers (Titze 1999) Demands on voice quality and vocal Voice problems in loading in different occupations teachers ? Quality Vocal loading Occupation High High Actors and classical singers High Average Radio- and TV journalists Questionnaires Prevalence : 11% n=1234 (Roy et al, 2004; 2005) Teachers, pre-school Average High 13 % n= 467 (Lyberg Åhlander et al 2010) teachers , telemarketers, priests 29 % n= 241 (Simberg et al 2001) Bank-, lawers, doctors, nurses Average Average Low High Industrial workers (e g., Gotaas, & Starr 1993; Ohlsson, 1988; Pekkarinen, m. fl., 1992; Russell, m. fl., 1998; Sapir, m. fl., 1993; Smith, m. fl., 1997; 1998) (After Vilkman 2000) 12 2

M Södersten, Karolinska Institutet, Rekjavik, Oct 12, 2012 Prevalence of voice disorders seems Pre-school teachers to increase � High background noise levels, poor room acoustics (Sala et al 2001; 2002) Year Percent teachers with voice problems � High background levels (Södersten et al 2002) 1988 12 % � Use of a loud voice and extensive voice use (Buekers, 2001 29 % 1998; Szabo Leroy, 2004 More pupils in the classes, increased noise levels, increased stress (Simberg m fl 2005) Voice disorder Teachers in � When the elaborate function of breathing- � music phonation-articulation has failed which affects � communication (Hammarberg,2008) sport � chemistry � When the voice does not function according to the needs ( Sala et al 2005; Vilkman 2000) higher prevalence of voice symptoms than teachers working in smaller groups (children with special needs) � Medical diagnosis (Smith m fl 1998, Thibeault m fl 2004) The most common diagnosis in teachers Number of patients in relationship to the � Acute Laryngitis number in the population � Functional voice disorder Occupation % Pat (n=1200) % in Sweden (4.5 milj) ♀ > ♂ ♀ ♀ ♀ ♂ ♂ ♂ � Vocal nodules All teachers 16.3 5.9 Pre-school teachers 3.1 1.4 Music teachers 1.3 0.2 (Fritzell, 1996) 17 3

M Södersten, Karolinska Institutet, Rekjavik, Oct 12, 2012 Voice disorders Complex etiology behind voice disorders Symtoms Consequencies � hoarseness � avoid to speak � strain � avoid working tasks Environmental � vocal fatigue � decreased working ability Individual work related � lump in the throat � sick leaves factors � throat clearing � avoid social contacts at work � voice is not stable and privately � cannot work � the voice is weak Voice � change of occupation � cannot be heard in noisy disorder environments Increase during voice use and decrease in voice rest (after Sala et al 2005) (Sala et al 2005; Simberg et al 2009; Södersten, Lindhe 2011; Vilkman 2000; 2004) Factors that affect our voice Physical environmental WORK ENVIRONMENT INDIVIDUAL problems in schools in Sweden Vocal demands Health, Diseases Ventilation Voice rest Medication Temperature Temperature Out doors Out doors Background noise Life habits Cleaning dust Room acoustics Personality Noise, acoustics Air quality Psychosocial sit. Inapropriate rooms Traffic Traffic Posture Voice training Lack of Lack of Stress Gender maintenance maintenance Technical aid Sunprotectio Sunprotectio Genetics n n After Sala et al 2005; Simberg et al., 2009; Vilkman 1996; 2004 % % SWEA, 2006 21 Teachers who because of noise can’t speak in Background noise masks speech normal voice intensity >25% of working time consequences: All 45 dB – speaker starts to raise voice intensity University High shool 55 dB – ok for speech communication (1m) Special needs 70 dB – loud voice to be heard (1m) Primary school Practical esthetic 85 dB – have to shout to be heard 0 10 20 30 40 50 60 % Arlinger, 1999 SWEA 2003 4

M Södersten, Karolinska Institutet, Rekjavik, Oct 12, 2012 ����� ���� Sound-treated booth What happens when one talk in high Noise background/acitivity noise? Noise + voice � Speak louder a filter which is exactly + like the channel above � Higher voice pitch Booth acoustics 10 dB 0 Voice? Voice! � More hyperfunctional and pressed voice -10 -20 -30 0 Hz 2000 4000 6000 8000 10000 May be hazardous to the voice Acquisition Ternström m fl 2002; 2006; FAS-projekt (2001-0341, 2002-0416) Some voice ergonomic recommendations Summary � Teachers are at risk to develop voice disorders � Plan the schedule with pauses for voice rest � Decrease noise levels at the source, try not to be � They have extremely high demands on the voice heard over noise, go closer to the listener related to their profession � Drink water, air humidity (elastic vocal folds) � Many employers and teachers do not seem to be � When you have a cold and are hoarse stay at home aware of that and rest the voice. � � To improve vocal health among teachers the Take early signs of symtoms seriousty knowledge has to increase about voice production, risk � If you are hoarse more than 2 weeks see a doctor – factors for voice disorders, and voice ergonomics important with a medical assessment (laryngologist/phoniatrician) � Prevention (for students during education and courses for working teachers) 5