Whistling while you work may be hazardous to your hearing

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Brook Clark
6 years ago
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Tasko, Ph.D. Donald S. Finan, Ph.D. Edward L.

Campbell Deanna K. Meinke, Ph.D. Michael Stewart, Ph.D. James E.

National Hearing Conservation Association Annual

findings and conclusions in this presentation have not

Occupational Safety and Health and should not be

1 Whistling while you work may be hazardous to your hearing Gregory A. Flamme, Ph.D. William J. Murphy, Ph.D. Stephen M. Tasko, Ph.D. Donald S. Finan, Ph.D. Edward L. Zechmann, M.S., PE, INCE Bd. Cert Adam R. Campbell Deanna K. Meinke, Ph.D. Michael Stewart, Ph.D. James E. Lankford, Ph.D. National Hearing Conservation Association Annual Meeting, San Antonio, TX, February 2017 Disclaimers: The findings and conclusions in this presentation have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy. The whistles utilized in this study were a convenience sample of instruments commercially available at the time of a prior study, and were owned by one of the researchers.

2 Introduction Sports officials report more problems with hearing and tinnitus. The sound output from the whistles used by sports officials is high. Some manufacturers report the sound power produced by their whistles, but the details of those measurements are not available. The spatial sound pressure distribution of whistles used by sports officials is not known. Users might be able to control noise exposure by using less effort. Flamme & Williams (2013); Martinez, et al. (2017 NHCA)

3 Analysis of Flamme & Williams Data T. Jerome, Senior Thesis, Brigham Young Univ. 2013

4 Research Questions 1. How much sound power is produced by whistles as a function of blowing effort? 2. By how much does the sound pressure distribution vary as a function of azimuth and elevation? 3. By how much do damage-risk criteria vary as a function of blowing effort and whistle?

5 Methods: 3-meter Hemispherical Array Rudyard, Michigan Field Site (28 microphones, 22 positions, 3 m radius)

6 Methods: De-identified Stooge (Blowhard) Whistle was directly over the center of the hemisphere. The Matrix (1999) Right Ear Microphone (60cm) Left Ear Microphone (10cm) Muzzle Microphone (60cm)

7 Methods: Whistles Number Make Model Pea Reported use, % 1 Acme Wide Mouth Thunderer Yes 8 2 Fox 40 Mini No 8 3 Fox 40 SuperForce CMG Yes 1 4 Fox 40 Sharx No 1 5 Fox 40 Pearl No 3 6 Fox 40 Mini CMG No 6 7 Seron P-38 Plastic No 1 8 Fox 40 Classic No 50 9 Fox 40 Sonik Blast CMG No 0 10 Fox 40 Classic CMG No Fox 40 Sonik No 0 12 Fox 40 Sonik Blast No 1 13 Molten Dolfin No 5 Reported use values after Flamme & Williams (2013)

Methods: Data Acquisition Hemisphere Microphones: 19 1/4 GRAS and B&K mics 6 1/8 GRAS and B&K mics 2 1/4 Ear-level microphones 1 1/8 Muzzle microphone Laboratory System:

8 Methods: Data Acquisition Hemisphere Microphones: 19 1/4 GRAS and B&K mics 6 1/8 GRAS and B&K mics 2 1/4 Ear-level microphones 1 1/8 Muzzle microphone Laboratory System: Custom-developed LabView software used for acquisition. Two National Instruments PXIe-4499 DAQ boards (10 V, 24 Bit, 200 khz) NI PXIe-1082 Chassis Two 8-channel PCB Signal Conditioners Model 483C05

9 Methods: Data Analysis Analyses MATLAB for data management and most processing AHAAH v. 2.1 for calculating AHU Stata for descriptive and inferential statistics Linear regression model, robust standard errors Dependent variables Sound power A-weighted sound power Peak LAeq8 AHAAH AHU-warned Independent variables Whistle model Effort level Trial

10 Results A Single Tweet Sound Pressure

11 Results Sound Pressure and Spectra High Effort Medium Effort Low Effort

12 Results Sound Pressure Distributions Low Effort Medium Effort Maximum Effort

13 Results Sound Power Comparisons Number Make Model Pea Sound Power, dba 1 Acme Wide Mouth Thunderer Yes Fox 40 Mini No Fox 40 SuperForce CMG Yes Fox 40 Sharx No Fox 40 Pearl No Fox 40 Mini CMG No Seron P-38 Plastic No Fox 40 Classic No Fox 40 Sonik Blast CMG No Fox 40 Classic CMG No Fox 40 Sonik No Fox 40 Sonik Blast No Molten Dolfin No 122 Note: These are summary values for high effort tweets

14 Results Sound Power Comparisons Across whistle models Relative to Specifications Sound Power Range, db re: W Mean: (IQR: ) Range: 109 to 123 Sound power values were underestimated for lowoutput whistles Effort level effect = 25 db Low medium: 15 db Medium high: 10 db

15 Results Peak Levels by Whistle and Effort

16 Results Peak Levels (Left Ear)

17 Results LAeq8 (Left Ear)

18 Results Maximum Permissible Exposures

19 Results Warned AHU

20 Results AHAAH-estimated Threshold Shift CTS = ln(ahu) Adams & Brazile (2017) N.B.: Number of tweets in game after Martinez, et al. NHCA 2017

21 Conclusions Sound power emissions of whistles range between 110 and 124 db re: W. Sound energy dissipates uniformly except behind the user. Effort level affected output by about 25 db Low effort levels nearly eliminate NIHL concern Manufacturer estimates of sound power were most accurate at high power levels. AHAAH warned AHU values and estimates of combined threshold shift were curiously high

Implications Photo credit: www.mccall.com; www.westvalleyview.

The hazard would be reduced or effectively eliminated if low efforts were used.

22 Implications Photo credit: Whistles used by sports officials are a risk factor for hearing loss. The hazard would be reduced or effectively eliminated if low efforts were used. Bystanders across a wide arc will have equal exposure. Problematic for wrestling and similar sports. The validity of AHAAH estimates of combined threshold shift could be tested easily.

23 Raise your hand if you have questions

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