noise-induced hearing loss and its implications for middle school, high school, and college band...

Noise-Induced Hearing Loss and Its Implications for Middle

School, High School, and College Band Directors

Ashley Waller

Objective

To determine the presence of excessive sound pressure levels in the classrooms of four music professors at the University of Tennessee.

To determine the presence of excessive sound pressure levels in the classrooms of three band directors at Halls Middle School and Halls High School.

Research Questions

1. What is the typical sound pressure level (SPL), measured in decibels (dBA), experienced by each teacher/professor in their respective teaching environments?

Research Questions

2. What are the maximum and minimum SPL (in decibels) experienced by each teacher/professor in their respective teaching environments?

Research Questions

3. What is the percentage of allowable daily noise dose experienced by each teacher/professor in their respective teaching environments in accordance with both The Occupational Health and Safety Administration (OSHA) and The National Institute for Occupational Safety and Health (NIOSH)/The American Conference of Governmental Industrial Hygienists (ACGIH) decibel exchange rates?

Research Questions

4. Were any of the teachers/professors exposed to sound pressure levels that exceeded the maximum allowable daily noise dose according to both OSHA and NIOSH/ACGIH scales?

Literature Review

Definition of Noise-Induced Hearing Loss (NIHL)

Hearing loss caused by continuous exposure to occupational noise.

(Sataloff and Sataloff, 1993)

Permanent hearing loss caused by prolonged exposure to high levels of sound. (Williot, 1991)

Irreversible and generally permanent hearing loss. (Royer, 1996)

Key Characteristics of NIHL

Almost always bilateral Once the exposure is discontinued, the

hearing loss does not continue to progress

Noise exposure over a long period of time is more damaging than interrupted exposure to noise.

(Owens, 2003)

Key Characteristics of NIHL

Excessive noise exposure has the potential to destroy the hair cells of the organ of Corti. These cells do not regenerate once they have been harmed or destroyed.

Individual susceptibility

(Owens, 2003)

Temporary Threshold Shifts (TTS)

Temporary loss of hearing due to brief exposure to excessive noise.

Previous level of hearing acuity will be restored after the ear repairs itself.

(Royer, 1996)

Permanent Threshold Shift (PTS)

Permanent loss of hearing due to exposure to excessive noise.

(Royer, 1996)

Decibel LevelsPoints of Reference

10 dB - Normal breathing 30 dB - Soft whisper 60-85 dB - Vacuum cleaner 90 dB - Tractor/Lawn mower 110 dB - Leaf blower/Chain saw 120 dB - Ambulance siren 125 dB - Causes pain 140 dB - Loudest recommended exposure WITH

hearing protection. 150 dB - Firecracker 180 dB - Rocket launching from pad

Decibel levels of 180 dB cause death of hearing tissue.

Industrial Regulation of Noise Exposure

Occupational Health and Safety Administration (OSHA): the maximum daily noise exposure level should not exceed 90 decibels (dBA) over an eight-hour period.

A 5-dBA exchange rate is followed.

(Behar, MacDonald, Lee, Cui, Kunov, & Wong, 1981)

OSHA Maximum Exposure Levels

Duration(hours/day)

Sound Pressure Level (dBA)

8 90

4 95

2 100

1 105

1/2 110

≤ 1/4 115

Industrial Regulation of Noise Exposure

The National Institute for Occupational Safety and Health (NIOSH) and the American Conference of Governmental Industrial Hygienists (ACGIH): the maximum daily noise exposure level should not exceed 85 dBA over an eight-hour period.

A 3-dBA exchange rate is followed.(Behar, MacDonald, Lee, Cui, Kunov, & Wong, 1981)

NIOSH/ACGIH Maximum Exposure Levels

Duration (hours/day)

Sound Pressure Level (dBA)

8 85

4 88

2 91

1 94

½ (30 min) 97

1/4 (15 min) 100

1/8 (7.5 min) 103

OSHA vs. NIOSH/ACGIH

According to OSHA, you can stand in an environment that is at 100 decibels safely for 2 hours (120 minutes)

According to NIOSH/ACGIH, you can only stand in an environment that is at 100 decibels for 15 minutes. Any exposure that lasts more than 15 minutes will cause damage.

Instances of NIHL in Music Teachers

Cutietta, Millin, Royse (1989): studied 32 high school band directors

41% of the band directors displayed some signs of NIHL

Instances of NIHL in Music Teachers

Cutietta, Klich, Royse, & Rainbolt (1994): compared audiograms of 104 music educators of

different genres (choral/general music, elementary instrumental, and high school instrumental)

20% of the vocal general subjects, 9 % of the elementary instrumental subjects, and 21% of the high school instrumental subjects displayed some NIHL.

Additionally, the high school instrumental subjects displayed a pattern of increasingly greater hearing loss as age increased.

Sound Pressure Levels Experienced By Music Teachers

Royer (1996): 50 sound pressure readings were taken in 23

different high school band rooms. The average sound pressure level (SPL) was

86.7 dBA. The sound pressure levels ranged from 77.8

dBA to 94.7 dBA. The 86.7 dBA average exceeded the

NIOSH/ACGIH regulations of allowable noise exposure.

Sound Pressure Levels Experienced By Music Teachers

Owens (2003): Sampled sound pressure levels in 10 Colorado

high school band rooms (63 SPL readings) 60% of the subjects experienced sound

pressure levels at or exceeding 90 dBA. All were exposed to sound pressure levels at

or exceeding 85 dBA. Maximum daily noise dosages:

OSHA standards: 69.2% NIOSH/ACGIH standards: 369.3%

Sound Pressure Levels Experienced By Music Teachers

Behar et al. (2004): 18 Canadian public school teachers were

surveyed. 78% of SPL readings exceeded the 85-dBA

limit. The average SPL experienced by the band

directors was 90.5, yielding a “safe” exposure time of only 2.1 hours (according to NIOSH/ACGIH).

Current Study

Materials and Methods

Subjects

Four professors from The University of Tennessee School of Music

Professor A: Associate Director of bands, director of the Concert Band, and professor of brass methods

Professor B: Assistant Director of bands, director of the Symphonic Band, and professor of undergraduate conducting and woodwind methods

Professor C: Applied Trumpet professor and director of the Trumpet Ensemble

Professor D: Applied Bassoon professor

Subjects

Three band directors from Halls High School and Halls Middle School.

Director A: Director of Bands at Halls High School. Director B: Assistant Director of Bands at Halls High

School and Halls Middle School. Director C: Director of Bands at Halls Middle

School.

Equipment

Brüel & Kjær Integrating Impulse Sound Level Meter, Type 2226 (manufactured by the Brüel & Kjær Company, headquartered in Nærum, Denmark)

Calibrated using a Quest Electronics CA-22 calibrator

Method

Two recording sessions were held for each subject’s class/private lesson.

Recordings were taken at random during each session (yielding 10-16 SPL recordings per class/private lesson). An average SPL was then calculated for each class/lesson.

Sound level meter was placed next to each director’s ear, approximately one to two feet behind the subject.

Recording Sessions at the University of Tennessee

Concert Band Symphonic Band Brass Methods II Conducting II Woodwind Methods II Trumpet Ensemble Trumpet Lessons (Professor C) Bassoon Lessons (Professor D)

Recording Sessions at Halls Middle School and Halls High

School Two 6th Grade classes Two 7th Grade classes Two 8th Grade classes HHS Concert Band class HHS Symphonic Band class HHS Indoor Drumline rehearsal (applies

to Director C only)

Results

Typical Sound Pressure Levels

What is the typical sound pressure level (SPL), measured in decibels (dBA), experienced by each teacher/professor in their respective teaching environments?

Typical Sound Pressure Levels

Professor A: 82.8 dBA—Concert Band rehearsals90.5 dBA—Brass Methods classes

Professor B:92.0 dBA—Symphonic Band rehearsals79.4 dBA—Conducting classes81.5 dBA—Woodwind Methods classes

Professor C:93.8 dBA—Trumpet Ensemble rehearsals88.3 dBA—Private lessons

Professor D:79.2 dBA—Private lessons

Typical Sound Pressure Levels (UTK)

50% of the typical sound pressure levels exceeded NIOSH/ACGIH maximum SPL of 85 dBA

100% of the high school band directors experienced sound pressure levels at or exceeding 85 dBA (Owens, 2003)

78% of the sound pressure levels exceeded the 85 dBA limit (Behar et al., 2004)

Typical Sound Pressure Levels (Halls)

6A: 89.1 dBA 6B: 88.2 dBA 7A: 87.0 dBA 7B: 89.9 dBA 8A: 87.9 dBA 8B: 85.8 dBA Concert Band: 87.9 dBA Symphonic Band: 89.9 dBA Indoor Drumline: 95.6 dBA

Typical Sound Pressure Levels

100% of the typical sound pressure levels exceeded NIOSH/ACGIH maximum SPL of 85 dBA

100% of the high school band directors experienced sound pressure levels at or exceeding 85 dBA (Owens, 2003)

78% of the sound pressure levels exceeded the 85 dBA limit (Behar et al., 2004)

Maximum and Minimum Sound Pressure Levels

What was the maximum and minimum SPL (in decibels) experienced by each teacher/professor in their respective teaching environments?

Maximum and Minimum Sound Pressure Levels (UTK)

Professor A:96.5 dBA; 54.5 dBA—Concert Band 89.0 dBA; 62.0 dBA—Brass Methods

Professor B:97.0 dBA; 79.0 dBA—Symphonic Band86.0 dBA; 70.0 dBA—Conducting92.0 dBA; 63.5 dBA—Woodwind Methods

Professor C:96.5 dBA; 90.5 dBA—Trumpet Ensemble94.5 dBA; 83.0 dBA—Private lessons

Professor D:83.0 dBA; 62.5 dBA—Private lessons

Maximum and Minimum Sound Pressure Levels (Halls)

6A: 93.5 dBA; 79.5 dBA 6B: 91.0 dBA; 82.5 dBA 7A: 90.0 dBA; 83.0 dBA 7B: 93.5 dBA; 83.0 dBA 8A: 91.0 dBA; 82.0 dBA 8B: 91.0 dBA; 64.0 dBA Concert Band: 92.5 dBA; 66.5 dBA Symphonic Band: 95.5 dBA; 53.5 dBA Indoor Drumline: 101.5 dBA; 57.5 dBA

Overall Maximum and Minimum SPL (UTK)

Maximum: 97.0 dBA Minimum: 54.5 dBA

Royer 1996: 94.7 dBA; 77.8 dBA

Overall Maximum and Minimum SPL (Halls)

Maximum: 101.5 dBA Minimum: 53.5 dBA

Royer 1996 94.7 dBA; 77.8 dBA

Percent Daily Noise Dose

What is the percentage of allowable daily noise dose experienced by each teacher/professor in their respective teaching environments in accordance with both OSHA and NIOSH/ACGIH decibel exchange rates?

Percent Daily Noise DoseOSHA (UTK)

0

5

10

15

20

25

30

Professor A Professor B Professor C Professor D

ConcertBrassSynphConductWoodwindTpt EnsLessons

Percent Daily Noise DoseNIOSH/ACGIH (UTK)

0

20

40

60

80

100

120

Professor A Professor B Professor C Professor D

ConcertBrassSynphConductWoodwindTpt EnsLessons

Professor C Daily Noise Dose (Trumpet Ensemble)

OSHA vs. NIOSH/ACGIH

0

20

40

60

80

100

120

OSHA NIOSH/ ACGIH

Tpt Ens

Percent Daily Noise DoseOSHA (Halls)

87 6

9

7

5

7

9

20

0

2

4

6

8

10

12

14

16

18

20

6A 6B 7A 7B 8A 8B C. B. S. B. I. D.

% DND

Percent Daily Noise DoseNIOSH/ACGIH (Halls)

24 2015

2918 11

1829

108

0

20

40

60

80

100

120

6A 6B 7A 7B 8A 8B C. B. S. B. I. D.

% DND

Director B (Indoor Drumline) Daily Noise Dose

OSHA vs. NIOSH/ACGIH

20

108

0

20

40

60

80

100

120

OSHA NIOSH/ ACGIH

I. D.

Sound Pressure Levels in Excess of Regulations

Did any of the teachers/professors experience sound pressure levels that exceeded the maximum allowable daily noise dose according to both OSHA and NIOSH/ACGIH scales?

Sound Pressure Levels in Excess of Regulations (UTK)

Only Professor C (Applied Trumpet/Trumpet Ensemble) experienced sound pressure levels that exceeded the maximum allowable dosage. Trumpet Ensemble rehearsals:

119.36% (NIOSH/ACGIH) 26.46% (OSHA) During one 75-minute rehearsal, Professor C receives

19.36% more noise exposure than is safely allowed (according to NIOSH/ACGIH).

Sound Pressure Levels in Excess of Regulations (Halls)

Hypothetical Situations

Hypothetical Case #1

Director X teaches only Concert Band and Symphonic Band Percent Daily Noise Dosage experienced

by Director X: 16% (OSHA) 47% (NIOSH/ACGIH)

Hypothetical Case #2

Director X teaches all middle school and high school bands, as well as Indoor Drumline (twice per week) Percent Daily Noise Dosage experienced

by Director X: 78% (OSHA) 272% (NIOSH/ACGIH)

Hypothetical Case #3

Director X teaches only the middle school ensembles Percent Daily Noise Dosage experienced

by Director X: 42% (OSHA) 117% (NIOSH/ACGIH)

Sound Pressure Levels in Excess of Regulations

Director B experiences sound pressure levels that exceed the maximum allowable dosage during Indoor Drumline rehearsals (twice per week).

Indoor Drumline rehearsals: 108.0% (NIOSH/ACGIH) 20.0% (OSHA) During one 120-minute rehearsal, Director B

receives 8.0% more noise exposure than is safely allowed (according to NIOSH/ACGIH).

Conclusions

1. None of the teachers/professors experienced an SPL in excess of the OSHA 90-dBA limit, and therefore none were at risk for NIHL based upon the OSHA standard.

2. Four the teachers/professors displayed a significant percent daily noise dose based upon the NIOSH/ACGIH 85-dBA limit.

Professor C: 119.36% for Trumpet Ensemble Professor B: 52.30% for Symphonic Band Director B: 108.0% for Indoor Drumline Director X: 117.0% (teaching all middle school

classes)

3. The discrepancy between the maximum noise exposure scales of OSHA and NIOSH/ACGIH signifies a need for standardization of industry noise exposure regulations.

So what can we do as teachers to protect ourselves?

Protective Equipment: Earplugs

Single-Use Earplugs Polyurethane Foam Inexpensive Available at most drugstores/major

retailers (ex. Walgreens, Wal-Mart, etc.)

Protective Equipment: Earplugs

Multiple-Use Earplugs Can be washed and reused multiple times. Usually made of rubber or silicon. Cost: Up to $15.00

Protective Equipment: Earplugs

Custom molded earplugs Allow for less distortion of sound than

disposable/other reusable earplugs. Contain filters that reduce decibel levels by

several decibels (ex. 9, 15, 25 dB) Must be fitted by a hearing care professional

Knox-Sevier Hearing Service

Rehearsal Room Design

Evaluate your rehearsal space for proper acoustical treatment.

Use materials in order to absorb excess sound Heavy draperies/curtains: Hang these over

whiteboards or concrete walls Carpet Three-dimensional relief art: Hang on side

walls Experiment with ensemble set-up to potentially

shield the director from excessive noise.

Rehearsal Room Design

According to Wenger: Rehearsal rooms should be a minimum of

2500 square feet. This should accommodate an ensemble of 60-70 members.

Ceilings should rise to 18-22 feet.

What are the dimensions of your rehearsal space?

What about our students?

Talk to our students about noise-induced hearing loss and their risks.

Encourage (if not require) our students to wear earplugs in certain rehearsals (drumline rehearsals in particular)

Encourage our students to reduce the amount of noise in their home environments (iPod usage especially!!)

Suggestions for Future Research

1. Determine the role of rehearsal room design and dimensions in the prevention of excessive noise exposure.

2. Experiment with ensemble seating arrangements in order to reduce noise exposure in both the conductor and the individual musicians.