Eeva Sala, MD, docent in phoniatrics eevasala@gmail.com 12th October - PowerPoint PPT Presentation

Possible ways to improve the voice ergonomics in schools Voice ergonomic assessment of the work environment, standards and laws Eeva Sala, MD, docent in phoniatrics eevasala@gmail.com 12th October 2012 at 15:10 ‐ 15:30 Eeva Sala 2012 Reykjavik 1

October 12 th 2012, 9:00 – 16:10 The Lecture Hall at the University Hospital in Reykjavík (Landspítali). Eeva Sala MD. Docent, Possible ways to improve the 15:10 – Phoniatrician in Turku 15:30 voice ergonomics in schools University Hospital, Turku Finland. Voice ergonomic assessment of the work environment, standards and laws Eeva Sala 2012 Reykjavik 2

Definition of Voice Ergonomics Communication & Voice ergonomics are part of broad ergonomic field Eeva Sala 2012 Reykjavik 3

Definition of Voice Ergonomics 1. Inspect and explore environment 2. Activity to develop and treat environment suitable and effective for speech communication Based on scientific evidence Multi ‐ professional collaboration Eeva Sala 2012 Reykjavik 4

Goal of Voice Ergonomics 1. Good conditions for effective speech communication – to prevent voice disorders and – to decrease handicap due to a voice disorder 2. Good conditions for speech hearing 3. To decrease adverse effect of noise Eeva Sala 2012 Reykjavik 5

Features of good voice ergonomic conditions • Vocal organs are not • Speech perception with overloading high enough word identification • No symptoms that – >80% decrease performance • Speech hearing happens • No risk for a disease (vocal without excess stress nodules, laryngitis) • No interference with concentration • No interference with memory • No interference with learning • No annoyance Eeva Sala 2012 Reykjavik 6

Voice ergonomic risk factors in the environment are found in fields of 1. Noise and acoustics 2. Indoor air quality 3. Working posture 4. Working culture and stress 7 Eeva Sala 2012 Reykjavik

Voice ergonomic risk factors in the environment are found in fields of Noise and acoustics Low noise levels and 1. 1. proper acoustics Indoor air quality 2. according to the activity Working posture Good indoor climate 3. 2. Possibilities for good Working culture and 3. 4. postures stress Working culture favoring 4. riskless courses of action What are the criteria for these? 8 Eeva Sala 2012 Reykjavik

1. Noise and acoustics • Communication Cognitive effects – Speaking • Learning – Speech hearing • Language learning • Cognitive effects • Attention – Learning – Memory • Memory • Auditory effects • Performance – Hearing damage • Motivation • Physiological effects – Pulse & Blood pressure – Stress hormone secretion • Sleep • Combined effects Eeva Sala 2012 Reykjavik 9

Speech perception in noise Identification of words % S/N Group PTA dB Quiet. ‐ 3 dB ‐ 8 dB ‐ 13 dB Normal hearing 9 98 95 79 48 Dip 4 kHz 9 96 87 75 27 Dip >1 kHz* 17 89 78 55 15 Sloping 43 89 81 50 6 Flat 47 89 81 54 12 Condukt. 48 97 97 85 60 PTA dB = Pure Tone Average *”Mild” hearing loss In a quiet environment speech perception is good but even small hearing loss and small amount of noise interfere with too much with hearing Eeva Sala 2012 Reykjavik 10 Pekkarinen (Sala) E, et al Scand Audiol 1990;19:31 ‐ 36.

Speech recognition in children Noise disturb speech identification more in children than in adults Word recognition 100 T 60 = 0.6 s 90 Ws = words in sentences 80 sW = single words 70 C = children n=29 Correct (%) 60 A = adults n=21 50 40 Ws C 30 Ws A 20 sW C 10 sW A 0 S/N S/N S/N S/N S/N Q 0dB +5dB +10dB +15dB +20dB Signal-to-noise Ström U, Sala E, Airo E. Speech recognition in background noise by day-care-children and adults. 2 5 th I ALP Congress. XXVth W orld Congress of the I nternational Association of Logopedics and Phoniatrics, Montreal August 5 .-9 ., 2 0 0 1 . Eeva Sala 2012 Reykjavik 11

Combined effects of noise and reverberation The younger the child the more difficulties with recognitions A Aikuisilla + 6 dB Lapsilla +15 ‐ +20 dB 12 v T 60 = 0.3 s 10% 9 v T 60 = 0.6 s T 60 = 0.8 s 6 v Key words in sentences 0.5 s ~ 10 ‐ 15% Neuman AC et al Ear&Hearing 2010;31(3):336 ‐ 344. Eeva Sala 2012 Reykjavik 12

1. Noise and acoustics Speaking in noise, forces to Lombard effect raise the voice 90 • which forces to increase 80 subglottic pressure 70 → bio mechanic forces increase 60 → risk for tissue damage increase 50 30 40 50 60 70 80 90 100 110 Background noise level dB (L Aeq ) ISO 9921 ‐ 1 Eeva Sala 2012 Reykjavik 13

2. Indoor air quality Poor indoor air affect mucous membranes • Dry air and dust ‐ > dry • Toxic substances ‐ > inflammation  Increase stiffness of the mucous membranes → Need to increase subglottic pressure → Bio mechanic forces increase → Risk for tissue damage increase Eeva Sala 2012 Reykjavik 14

3. Working posture Poor working posture • Increases muscle tension → Bio mechanic forces increase → Risk for tissue damage increase • Prevent barrier free muscle function Eeva Sala 2012 Reykjavik 15

4. Working culture Poor working culture • Excess voice use • Need to raise the voice – Long speaking distances – Speaking in noise • Lack of possibilities to rest Eeva Sala 2012 Reykjavik 16

How to evaluate voice ergonomic risk factors in work environment? • There is a tool – how to do it – criteria for acceptable conditions The Voice Ergonomic Assessment Handbook and checklist Sala E Hellgren U ‐ M Ketola R Laine A Olkinuora P Rantala L Sihvo M Eeva Sala 2012 Reykjavik 17

Voice ergonomic assessment Number of risk factors studied Fields of voice ergonomic Number of risk Total risk factors in factors Per cent risk factors the study in the test 1 . NOISE 18 720 34 (max. score 18x40 = 720) 2. INDOOR AIR QUALITY 16 640 30.2 (max.score 16x40=640) 3. POSTURE 11 440 20.8 (max.score 11x40 = 440) 4. WORKING CULTURE 8 320 15.1 (max. score 8x40 =320) Total 53 2120 100 (max. score 720+640+440+320 =2120) Eeva Sala 2012 Reykjavik 18

Several forms Example 1. Noise Summary tables in each field 1.1. Evaluation of the noise caused by ventilation and equipment 1.2. How to decrease the disturbance caused by the noise 1.3. Evaluation of the noise from outside or from adjacent rooms 1.4. Evaluation of the reverberation 1.5. How to measure the noise caused by ventilation and equipment 1.6. How to measure the noise from outside or adjacent rooms Eeva Sala 2012 Reykjavik 19

1.1. To evaluate the noise caused by ventilation and equipment   Observation  Question  Is not clearly  Is clearly Is the ventilation noise clearly audible? audible audible  Observation  Question  No, there are  Yes, there Are there other noisy equipment? not are  Heating  Air conditioning  Water pipes  Drains  Lamps  Elevators  Other equipment, What?  Observation  Question  No, there are  Yes, there Are there other noisy equipment? not are  Computer  Printer  Video projector  Overhead projector  Document camera  TV  Radio  Other, what?  Observation  Question  No, there are  Yes, there Are there other noisy equipment? not are  Woodwork machines  Metallurgy machines  Household machines  Musical instruments  Toys  Physical exercise equipment  Other, what? Eeva Sala 2012 Reykjavik 20

 1.1. To evaluate the noise caused by ventilation and equipment Instruction : Listen to the equipment in the position where the speaker usually is speaking. In the room, nobody else is allowed to stay than those who make the assessment. Listen to one equipment at a time and turn off other equipment while listening to (also the heating, air conditioning, electricity etc.). Make a tick at the loud equipment or record another noisy equipment. Criteria: If noise is clearly audible, it is very likely that level, the speaker has to raise her/his voice. While doing the screening, try to find out if it is possible to reduce the harmful effects of noise, go to see form 1.2. It would be wise to start from the noisiest equipment. Recommendations to the measures:  Take contact wit the employer to  measure the level of the noise, go to see form 1.5.  to check and to readjust the ventilation/air conditioning system  to buy equipment that are quiet  to buy lap tops  other  Eeva Sala 2012 Reykjavik 21

2. Indoor air quality 1. How to measure room temperature. 2. How to evaluate if the air is dusty 3. How to evaluate if there are odors or moisture damages 4. How to evaluate if ventilation is working badly and if the room is drafty 5. How to evaluate and measure the air humidity Eeva Sala 2012 Reykjavik 22

3. Postures 1. Postures while speaking and singing Eeva Sala 2012 Reykjavik 23

4. Working culture 1. Use of loud voice – long speaking distance 2. Use of loud voice – noisy equipments 3. Voice rest and relax 4. Stress Eeva Sala 2012 Reykjavik 24

5. Aids 1. Need of sound amplifier 2. Need of headset or hands ‐ free when using telephone Eeva Sala 2012 Reykjavik 25

Is there a need to improve? • How are the voice ergonomic conditions in school classrooms? Eeva Sala 2012 Reykjavik 26

Voice ergonomic risk factors in school classrooms N=40 60 50 Percentage of findings 40 30 52 44 20 32 33 30 10 0 Working culture Indoor air Working Noise and Stress quality postures reverberation Eeva Sala 2012 Reykjavik 27