Finnish voice ergonomic studies Le Leena na R Ran antala tala - - PowerPoint PPT Presentation

Finnish voice ergonomic studies

Le Leena na R Ran antala tala Eeva va Sal ala

Surveys, Laboratory study, Field studies, Rehabilitation study (coming)

Surveys

• Several studies
• Aims e.g.

– Voice symptoms and voice related disorders

– Working culture

– Genetic vs. environmental origin

• Participants:

– teachers – nursery school teachers – teacher students

Laboratory study

Laboratory study: voice loading

• Pa

Part rticip icipants nts

– 40 males and 40 females – Normal speakers

• Lo

Loading ding

– 5 x 45 minutes + 2 rest periods – Differ fferent ent condi ditions tions:

• Sound pressure levels: ’conversation’ level and

loud

• Postures: sitting and standing
• Indoor air humidity: dry and humid

Field studies

Field study: loading changes

• 2 studies for female teachers
• 33 and 79 participants
• Voice symptoms and phoniatric examination
• Voice production

– Recordings » teaching speech (during lessons) » text reading, prolonged phonation (outside lessons)

• 1 study for male teachers
• 22 participants
• 1 study for call centre advisers
• 24 females, 8 males
• 4 recordings during a workday

Voice ergonomics in workplaces

Study: Voice ergonomic assessment

• 2 studies: nursery schools and schools
• Voice risk factors assessed

– (1) noise, (2) indoor air quality, (3) working postures, (4) working culture (included stress) and (5) a lack of using sound amplifier

• Voice symptoms
• Voice use

– during work – before and after a working day

Coming

Voice therapy: carrying voice ergonomics/good vocal habits into teaching culture

• Female teachers

– 30 voice therapy with special emphasis

• n carry over

– Controls

• 30 with ‘traditional voice therapy’
• 30 without therapy
• 2 year follow up

What do we know now?

Results

Voice symptoms

• Environmental factors effect more than genetic ones
• Voice disorders have increased during last years
• Allergy is more typical in those with voice symptoms
• Occupational health care does not know how to treat

voice disorders

• Teachers:

– 42 - 29 % symptoms frequently

• Nursery school teachers:

– 71 % symptoms frequently, 11 % organic changes in the larynx

• Teachers student

– 20 % voice symptoms, 19 % organic changes in the larynx

Voice loading

• Voice symptoms arise
• Voice rest

– helps to recover (laboratory study) – the effects of voice risk factors are found in the morning (field study)

Voice loading effects

• Voice production changes

– Increase of

• F0 (pitch) and SPL (loudness)
• effort to produce voice (change of glottal

pulse)

• hyperfunctional voice quality (spectrum levels)

– Decrease of

• Perturbation (jitter and shimmer) increases in

vocal fold vibration

Voice ergonomics in work places

• Nursery school

– have high background noise levels – 17 % of the rooms in day care centre had adequate room acoustics (measured by RASTI)

• Nursery school teachers vs. nurses

– talk longer (40 % of the working time) than nurses (28 %) – talk louder (78 dB) than nurses (72 dB)

• Many voice ergonomic risk factors in the

classrooms

Voice ergonomics and voice health

Teachers

– The more voice ergonomic risk factors in the classroom

• more voice symptoms
• higher SPL (voice loudness) before and after a

workday

– Poorer indoor air quality, more laryngitis

Carry over study: preliminary results

• 8 teacher with carry over method/ 5

traditional

– Both therapies affect

• Voice quality towards more economical voice

production (perceptual evaluation)

• Subjective evaluation (VAS-scale): less voice

tiredness

– ½ yr after therapy: more constant results with carry over method