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Life cycle analysis of noise and hearing handicap in Finland

Esko Toppila1, Ilmari Pyykkö2, Rauno Pääkkönen1

1=Finnish Institute of Occupational Health2=University of Tampere

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Noise and Work

Military branch

Industry

Services

Schools

Environment

Annoyance Communication Hearing loss

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Characteristics of work in 20th century (Ruben 2000)

0

10

20

3040

50

60

70

80

90

1900 1950 2000

Physical Communication

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Hearing handicap

• Symptoms– hearing loss– hyperacusia– difficulties in sound localisation– tinnitus– reduced speach intelligibility especially in ambient noise– diplacusis – --.

• Symptoms start typically in age of 45– First affect in poor acoustical conditions

95,0

85,0

75,0

65,0

55,0

45,0

35,0

25,0

15,0

300

200

100

0

/

Classification of hearing handicaps

• Non-noise induced (>10 % of people under 65)– Presbyacusis

• Often genetic background• CNS infection, ear infection• sociocusis

– Middle ear problems (seldom)

• Noise induced (<10 % of workers in noise over 85 dB)– Acute trauma– Chronic trauma (The "real" hearing handicap)

• Evaluation based on audiogram• Tinnitus .. do not affect typically

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Social effects of hearing handicap

• Reduced speech intelligibility– Do no understand especially in ambient noise– Social isolation– Mental problems (. 2x)

• Tendency to believe that others make fun– Increased accident risk

• Misunderstanding instructions• Failure to hear warning signals

– Reduced career opportunities• Training difficult speech• is not understood

– Increased risk of unemplyoment• " dumb people do not work here"

• Reduced capability to localize sounds– Increased accident risk

• if moving machines around– Reduced speech intelligibility

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Social effects of hearing handicap

• Tinnitus– Increased annoyance– may interfere with warning signals– sleep disturbance– avoidance of social noisy events

• concerts, public events,….

– …

• Hyperacusia– stress– avoidance of social noisy events

• concerts, public events,…

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Self evaluated hearing

Q114

3.53.02.52.01.51.0.5

Mea

n le

vel a

t sp

eech

fre

qu

enci

es (

0.5-

2 kH

z)

60

50

40

30

20

10

0

-10

Normal Mild Moderate

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Quality of life and self-evaluated hearing

115161257147N =

Self-evaluated hearing

Deafalmost deaf

Some difficulties

Minor problems

Normal

EQ

-5D

th

erm

om

ete

r

80

70

60

50

40

30

20

/

Effect of hearing in different populations

0.5

0.55

0.6

0.65

0.7

0.75

0.8

0.85

0.9

TAYS<66 Laminoijat Puusepät KorkeaKommunikaatio

Normaali

Lievä

Kohtalainen

Vakava

0.5

0.55

0.6

0.65

0.7

0.75

0.8

0.85

0.9

Users ofhearing aids

Physical workers

Technicians High commworkers

Normal

Mild

Moderate

Almost deaf

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Life cycle of noise

NosocusisDiscos and concertsEquipment

Infections

Conscript noise

Life styleWork noise

Ambient noise

Ambient noiseFree time noise

Earlyretirementdementia

(0-5 y) (20-30 y)(45-68 y)

Accumulation of noise effects

- Vaccination- Personal pacifier

-Exercise-Noise limits in discos-Teaching attitudes

-Hearing protection-Healthier life style

-Personal hearing solutions- Office noise

Earlier accessto hearing aids

-Better hearingprotection

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Estimates of the size of the problem

• Number of conscripts with hearing loss >20 dB at any frequency has increased from 13 % to 20 %

– Noise ?– Life style factors (Young age cholesterol RR=7.2, Pyykkö et

al 2007)– Kindergarten infections ?

• Call centers (Toppila et al 2008)– 15 -25% complaints about hearing– Demanding job -> subclinical hearing loss important

• Protection against work noise not efficient– In elderly people in noisy occupations overpresented in

hearing aids fitting– Factor ~2

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Size of problem

• Finland looses 21 B€ every year because of early removal from workforce (Ahonen, Vainio 2010)

• Hearing impairment seems to be involved in 5-15 % of the cases

– Annual cost 2.1 B€ (Extrapolated to US 176 B$)– Mostly from work not done– Direct costs 200-400 M€ (Extrapolated to US 2.5B$)

• These calculations exclude – Lost career opportunities– Effect on pensionnaires

• earlier dementia etc.

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Hearing loss, removal from workforce and statistics (Total workforce 2.2 M)

Toistuvatkorvatulehdukset

Vapaa-ajanMelu

Nuoren iänkolesteroli

Riskitekijät

Risk group

Asevelvollisuusmelu

300-500

300-500

100-400

700

1000

1000

Unempolyment

Hearing loss 50%

130%

3000

2000Ei työmelua: 1600 000

Ototoksinenlääkitys

Chemicals, vibration, medication

30-40?

Statistics

Noise caused accident0%

70

<10

500?

Repeatedinfections

Free time -noise

Young agecholersterol

Risk factorsj

Worknoise

for earlyremoval from workforce250 000

Conscript noise

300-500

300-500

100-400

700

1000

1000

Early retirement

NIHL

50%

130%

3000

2000

Work noise 400 0000

No worknoise: 1600 000

Accident

Dementia

Ototoxicmedication

Combined exposure

30-40?

Stat

A0%

70

<10

500?

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Potential for savings

• Reduction of sociocusis, early age effects 30%• Reduction of Noise Induced Hearing Loss 70 %

– Not 100 % because of overdiagnosis

• Totally in work force ~35%– 750M€/y (US 62 B$)

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Discussion

• Noise is underestimated problem in modern societies– Affects people with hearing handicap in harsh

communication environments

• Cause for underestimation– Affects several factors– Never the most important factor but ranked 3-5 (de

Hollander et al 1999)

• To reduce the adverse effects of noise– work noise protection– reduction of nosocusis– protection of free time noise