M Sdersten, Karolinska Institutet, Oct 13, 2012, Rekjavik Voice - PDF document

M Södersten, Karolinska Institutet, Oct 13, 2012, Rekjavik ”Voice team” Karolinska University Hospital and Karolinska Institute Voice ergonomics work in Sweden. What we have done and what is the need ? 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 13 2012 Södersten M, ELS 2012 2 1. Background Content What has been done in Sweden and what is needed Fritzell had a deep interest in the field of voice problems and occupations. 1 In occupational voice research 1970’s supervised many theses, e.g., prevalence of voice disorders in different occupational groups. 2 In clinical work National study to obtain statistics among patients at the phoniatric departments in Sweden. Based on research he claimed the importance of preventive voice care for teachers . Prof Björn Fritzell Fritzell B. (1996) Voice disorders and Gender differences in voice occupations. Log Phon Vocol 2:7-12. Investigated occupation, age and gender in 1200 Women have patients at their first visit to voice clinics � Shorter vocal fold - higher frequency, more vocal Results fold collisions � Teachers were the largest group of patients. � Shorter vocal tract (the resonance tupe from the � 76 % were women vocal folds to the lips) – ”lighter” voice quality and weaker voice � Most common diagnoses: � Less degree of hyaluronic acid in the vocal folds – � Phonastenia 72 % women less dampening of the vibrations � Vocal fold oedema 89 % ” � Vocal fold polyp 59 % ” Work in vocally demanding occupations 97 % ” � Vocal nodules More vulnerable to voice problems (?) This study ”repeated” 2011 – same results 1

M Södersten, Karolinska Institutet, Oct 13, 2012, Rekjavik Current research areas 1. Background Long-term measurement of voice with � Ohlsson A-C. (1988) Voice and work environment: focus on voice production in high Towards an ecology of vocal behaviour. Doctoral thesis, Gothenburgh University background/actitivity noise (Research group in Stockholm) New: Voice Accumulator � Teachers voice and room acoustics in to measure vocal behavior during schools work for telephone operators, (Research group in Lund and Denmark) nurses, speech pathologists, welders Preventive voice care in teachers � (Research group in Gothenburgh) Voice Accumulator – to measure voice use in Fundamental frequency during and after work occupational and non-occupational settings Subjects 12 vocally healthy pre- school teachers Variables � Fundamental frequency (Hz) � Phonation time (s and %) Diary - activities Ohlsson 1988, Buekers et al 1995; Szabo Leroy 2004; Szabo Portela (submitted) Szabo Portela et al (submitted) Average fundamental frequency during and Phonation time in % during and after work after work for healthy pre-school teachers for healthy pre-school teachers (n=12) (n=12) 20 320 18 300 16 Fonationstid (%) 14 280 12 260 F0 (Hz) 10 240 8 220 6 200 4 180 2 160 0 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 At Work After Work At Work After Work Szabo Portela et al (submitted) Szabo Portela et al (submitted) 2

M Södersten, Karolinska Institutet, Oct 13, 2012, Rekjavik Project: Female voice in pre-school settings Similar results when measuring 56 teachers voice use ( ��������������������������������������������������� during work and leasure ������������������������������� Hunter EJ, Titze IR. (2010) Variations in intensity, fundamental Background: frequency, and voicing for teachers in occupational versus 1970s : many new large day care centers were built with nonoccupational settings. Journal of Speech, Language, and and were followed by architects and acousticians Hearing Research. 53, 862–875. 1980s : To high noise levels – interventions – decrease the background/activity noise by 10 dB Important information in discussions if a voice disorder should be classified as a work disease 1990s : Larger groups of children, increase of noise levels Noise increased to 70-80 dB common Binaural DAT recording Noise levels at 10 pre-schools MICROPHONES 76 dBA (73-79) ������������ �������� �� ���������� ����� ���� ��������� DAT Granqvist 2003, Södersten et al 2002, Ternström et al 1994 Also used for measuring childrens’ voices in pre- school settings (McAllister et al 2009) Södersten et al 2002 Södersten et al 2002 Background/Activity noise Voice intensity in habitual reading and during work 90 p<.001 Noise level Consequences for the speaker 85 Leq dB (at microphones) � 40 dBA starts increasing the voice intensity 80 � 55 dBA* normal and audible (1 m) voice intensity � 70 dBA high intensity to be heard at 1 m. 75 � 85 dBA has to shout to be heard 70 * Good for speech communication 65 60 Mean (SD) Baseline reading During Work AFS 2008, 2005 Sala et al 2005 Södersten et al 2002 17 3

M Södersten, Karolinska Institutet, Oct 13, 2012, Rekjavik Fundamental frequency in habitual voice and during work Conclusions p<.001 300 � Preschool teachers very vocally demanding work 280 260 � Background/Activity noise – found to be a risk 240 factor 220 � Importance of field studies 200 180 � Time-consuming and problematic method 160 140 120 100 Baseline reading During work Mean (SD) Szabo Leroy 2004, Södersten et al 2002 Södersten et al 2002 Noise level measure at the ears of the children at three preschools J Voice McAllister et al 2009 Vocal loading in background noise at different work environments – laboratory studies Sten Ternström, Mikael Bohman Dept of Speech, Music, Hearing, Royal Institute of Technology, Stockholm Maria Södersten, Carina Aronsson Dept of Logopedics and Phoniatrics Karolinska Institutet Supported by The Swedish Council for Working Life and Social Research McAllister et al 2009 4

M Södersten, Karolinska Institutet, Oct 13, 2012, Rekjavik ����� Working environments with high background SOUND-TREATED BOOTH window or activity noise levels movie screen DAT Daycare centres 76 dB sub-woofer Industries 85 dB Prompting mic B rod Operator Pubs 80-90 dB PC running mic A LCD slide show projector spoken subject commands Acquisition Operator PC with DSP Ternström et al 2006 Recording conditions Subjects Background Leq Situation Vocally healthy adults 1. Quiet < 30 Quiet classroom � 12 women, 30 to 54 years (mean age 44) � 11 men, 20 to 53 years (mean age 34) 2. Soft 70 Outside a ventilation room 3. Day-care 76 Noisy day-care 4. Disco 87 A rowdy night 5. Loud 85 Inside a ventilation room Södersten et al 2005; Ternström et al 2006 ���������� Sound-treated booth Questionnaire Noise � Did you make yourself heard? Noise � Was your speech/voice effortful? + voice � Did you feel vocal fatigue or strain in you a filter which is exactly + voice/throat during the reading? like the channel above Booth acoustics 10 dB Answers on a 100 mm visual 0 Voice? Voice! -10 analogue scale -20 (not at all – extremely) -30 0 Hz 2000 4000 6000 8000 10000 Acquisition (Bohman et al 2002, Ternström et al 2002) 5

M Södersten, Karolinska Institutet, Oct 13, 2012, Rekjavik Results - male/female differences Acoustic analyses Methods: � Males were 3-5 dB louder throughout. Phonetogram Phog, Swell (Saven Hitech AB) Females 50% higher pitch (in Hz) � � Females felt more strain during reading Variables � Females felt they had to exert their voices more � voice sound pressure level � Males were more confident of having been heard � fundamental frequency � phonetogram area The results support the notion that females are more � total reading time vulnerable to vocal overload in noisy environments � phonation ratio (phonation time expressed in percent of the reading time) � acoustic spectrum Södersten et al, 2005 Ternström et al, 2006 Voxlog – portabel voice accumulator Current projekt: Umeå universitet To identify risk Fredric Lindström Accelerometer factors for voice disorders Karolinska Universitetssjukhuset/KI and microphone Maria Södersten Göteborgs Universitet Kerstin Waye Persson KTH Stockholm � Fundamental frequency (Hz) Sten Ternström � Phonation time (s and %) � Vocie Intensity (dB) Linköpings Universitet Anita McAllister � Level of noise (dB) Lunds Universitet Support: Forskningsrådet för Viveka Lyberg Åhlander arbetsliv och socialvetenskap (FAS) Lindström et al (2011) Sonvox (2012) Thorsdotter 2011 Subjects : Questions 30 patients with work-related voice disorders Is vocal behavior affected by the level of the background/activity noise? 30 vocally healthy controls Does vocal loading measured with ”accumulated cycle matched as regards gender and work place) dose” correlated with subjective symtoms of vocal fatigue Are there differences in voice use � in occupational and non-occupational settings ? � In patients with voice disorders and healthy controls? 6