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

15:10 – 15:30

October 12th 2012, 9:00 – 16:10 The Lecture Hall at the University Hospital in Reykjavík (Landspítali). Possible ways to improve the voice ergonomics in schools Voice ergonomic assessment of the work environment, standards and laws

Eeva Sala

• MD. Docent,

Phoniatrician in Turku University Hospital, Turku Finland.

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Definition of Voice Ergonomics

Communication & Voice ergonomics are part of broad ergonomic field

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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

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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

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Features of good voice ergonomic conditions

• Vocal organs are not
• verloading
• No symptoms that

decrease performance

• No risk for a disease (vocal

nodules, laryngitis)

• No interference with

concentration

• No interference with

memory

• No interference with

learning

• No annoyance
• Speech perception with

high enough word identification

– >80%

• Speech hearing happens

without excess stress

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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

1.

Noise and acoustics

2.

Indoor air quality

3.

Working posture

4.

Working culture and stress

1.

Low noise levels and proper acoustics according to the activity

2.

Good indoor climate

3.

Possibilities for good postures

4.

Working culture favoring riskless courses of action What are the criteria for these?

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• 1. Noise and acoustics
• Communication

– Speaking – Speech hearing

• Cognitive effects

– Learning – Memory

• Auditory effects

– Hearing damage

• Physiological effects

– Pulse & Blood pressure – Stress hormone secretion

• Sleep
• Combined effects

Cognitive effects

• Learning
• Language learning
• Attention
• Memory
• Performance
• Motivation

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10

Speech perception in noise

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

Identification of words %

Pekkarinen (Sala) E, et al Scand Audiol 1990;19:31‐36.

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 S/N

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Speech recognition in children

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Word recognition

10 20 30 40 50 60 70 80 90 100 S/N 0dB S/N +5dB S/N +10dB S/N +15dB S/N +20dB Q Signal-to-noise Correct (%) Ws C Ws A sW C sW A

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 .

T60 = 0.6 s

Ws = words in sentences sW = single words C = children n=29 A = adults n=21

Noise disturb speech identification more in children than in adults

Combined effects of noise and reverberation

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6 v 9 v 12 v A Aikuisilla + 6 dB Lapsilla +15 ‐ +20 dB T60 = 0.3 s T60 = 0.6 s T60 = 0.8 s Key words in sentences 0.5 s ~ 10‐15%

Neuman AC et al Ear&Hearing 2010;31(3):336‐344. 10%

The younger the child the more difficulties with recognitions

• 1. Noise and acoustics

Speaking in noise, forces to raise the voice

• which forces to increase

subglottic pressure

→ bio mechanic forces increase → risk for tissue damage increase

50 60 70 80 90 30 40 50 60 70 80 90 100 110

Background noise level dB (L Aeq)

ISO 9921‐1

Lombard effect

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• 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

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• 3. Working posture

Poor working posture

• Increases muscle tension

→ Bio mechanic forces increase → Risk for tissue damage increase

• Prevent barrier free muscle function

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• 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

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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

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Voice ergonomic assessment

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Fields of voice ergonomic risk factors Number of risk factors studied

Number of risk factors in the test Total risk factors in the study Per cent

• 1. NOISE

(max. score 18x40 = 720)

18 720 34

• 2. INDOOR AIR QUALITY

(max.score 16x40=640)

16 640 30.2

• 3. POSTURE

(max.score 11x40 = 440)

11 440 20.8

• 4. WORKING CULTURE

(max. score 8x40 =320)

8 320 15.1

Total (max. score 720+640+440+320 =2120)

53 2120

100

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1. Noise

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

Several forms Summary tables in each field Example

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1.1. To evaluate the noise caused by ventilation and equipment 

 Observation  Question

Is the ventilation noise clearly audible?

 Is not clearly audible  Is clearly audible

 Observation  Question

Are there other noisy equipment?

 Heating  Air conditioning  Water pipes  Drains  Lamps  Elevators  Other equipment, What?  No, there are not  Yes, there are

 Observation  Question

Are there other noisy equipment?

 Computer  Printer  Video projector  Overhead projector

 Document camera  TV  Radio  Other, what?  No, there are not  Yes, there are

 Observation  Question

Are there other noisy equipment?

 Woodwork machines  Metallurgy machines  Household machines  Musical instruments  Toys  Physical exercise equipment  Other, what?  No, there are not  Yes, there are

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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 

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• 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

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• 3. Postures
• 1. Postures while speaking and singing

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• 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

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• 5. Aids
• 1. Need of sound amplifier
• 2. Need of headset or hands‐free when using telephone

Is there a need to improve?

• How are the voice ergonomic conditions in

school classrooms?

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Voice ergonomic risk factors in school classrooms N=40

52 44 33 32 30

10 20 30 40 50 60

Working culture Indoor air quality Working postures Noise and reverberation Stress

Percentage of findings

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How to eliminate?

• To plan and build work environment and

learning/teaching environment according to a good voice ergonomic standard

• To perform voice ergonomic assessment in work

environment at regular intervals

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What it needs?

• To create a standard for good voice ergonomics
• It needs the knowledge about what are the criteria for a good voice

ergonomics

• Information and schooling

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To create a standard for good voice ergonomics

• 1. Noise and acoustics
• 2. Indoor air quality
• 3. Working posture
• 4. Working culture and stress

It’s multiprofessional work

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In your workplace, are there the facilities according to the new Communication Standard? No, what is that?

”I do not know.”

”How you get skillful workers?”

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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

1.

Low noise levels and proper acoustics according the activity

2.

Good indoor climate

3.

Possibilities for good postures

4.

Working culture favoring riskless courses of action What are the criteria for these?

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• 1. Noise and acoustics
• 1. The noise caused by

ventilation and equipment

• 2. The noise from outside
• r from adjacent rooms
• 3. The acoustics

/reverberation

• 4. Activity noise

1. Noise levels should not exceed 33 LAmax / 28 LAeq 2. Sound insulation should be 48 dB between classrooms 3. Reverberation time should be 0.4‐0.6 s and STI values ≥0.80 in classrooms 4. Measure activity noise: activity noise is not allowed to exceed 65 dBLAeqwhile talking

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• 2. Indoor air quality
• 1. Room temperature
• 2. The air dustiness
• 3. Odors and moisture

damages

• 4. Ventilation and draft
• 5. The humidity of the air

1. In summer 20‐26oC and in winter 20‐23oC 2. No visible dust on surfaces

• r in the air

3. The air is fresh without any

• dors

4. Ventilation volume according to room size and amount of people. No draft. 5. Relative humidity in summer 25‐60% and in winter 25‐ 45%

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• 3. Working posture
• 1. Furniture
• 2. Equipment
• 1. Furniture: adjustable

tables and chairs

• 2. Equipment: possibility to

place to positions for a good posture

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• 4. Working culture
• 1. Use of loud voice – long

speaking distance

• 2. Use of loud voice – noisy

equipment

• 3. Voice rest and relax
• 4. Stress
• 5. Activity noise

1. Arrange the group members so that the distance is as short as possible 2. Eliminate noisy equipment near the speaker and listeners 3. Have a voice rest min 5 minutes/1 hour 4. Watch stress level and make acts to decrease it 5. Monitor activity noise levels: activity noise is not allowed to exceed 65 dBLAeq while talking

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• 5. Use of aids
• 1. Need of sound

amplifier

• 2. Need of headset or

hands‐free when using telephone

1. Sound amplifier available when raised voice is needed 2. Hands‐free is available when talking in the telephone more than 10%

• f time or over 5 min/call

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In your workplace, are there the facilities according to the new Communication Standard? Yes, of course, there are!

”Workes chose the best work places” ”How you get skillful workers?”

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It needs information and schooling

• To developers
• To planners of buildings
• To those who are building the spaces
• To planners of furnishings and decoration
• To those who buy equipment
• To those who plan the work
• To employee

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Barrier free environment and good practices of activity while working

Scientific knowledge Multi‐professional collaboration

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How much?

Not much ‐ Things only will be done according to the knowledge

SEK SEK SEK

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