10/17/2018 Cory Portnuff, AuD, PhD, CPS/A Board Certified, Clinical Audiologist UCHealth Assistant Clinical Professor Department of Otolaryngology, School of Medicine University of Colorado Denver Following this presentation, learners should be able to explain the factors which contribute to music-induced hearing loss and describe the state of the science in this field. Following this presentation, learners should be able to implement a program of hearing conservation for musicians with a focus on reducing the risks of music on the auditory system. 1
10/17/2018 This presentation will discuss commercially available and some not commercially available products. Endorsement of any products is mine alone and does not necessarily reflect the opinions of UCSF, the University of Colorado School of Medicine, UCHealth, ASHA, AAA or anyone else. Metabolic “overload” Glutamate ototoxicity Cellular apoptosis/necrosis is induced ▪ Heat shock proteins ▪ Oxidative stress Mechanical hair-cell damage Stereocilia damage Supporting cell damage Micro-structural damage to stria vascularis Vascular break-down leads to cochlear hypoxia ▪ Decreased vasodilators, disruption of endothelial cells 2
10/17/2018 Acoustic trauma Stereocilia sheared off TM perforations Separation of organ of Corti from basilar membrane (>132 dB SPL) Uncommon with music exposure! Few studies of music effects on auditory pathophysiology Most studies use auditory biomarkers Hearing loss Tinnitus OAEs 3
10/17/2018 “Temporary” effects of music • TTS • Amplified music (Opperman et al, 2006) • Dance clubs (Gunderson et al, 1997; Meecham & Hume, 2001) • Temporary OAE change • Aerobics classes (Torre & Howell, 2008) • PLD use (Keppler et al, 2010; Bhagat & Davis, 2008) “Temporary” effects of music • Tinnitus • Dance clubs (Holgers & Pettersson, 2005) • Concerts (Chung, et al., 2005; Quintanilla-Deck, et al., 2009). • MP3 player use 4
10/17/2018 Permanent effects of music How do we quantify effects? • Cross-sectional research with large study groups •Can see changes between groups • Longitudinal studies •Can see changes within a group Permanent effects of music • Hearing thresholds • Classical musicians – 52.5% have “notch” (Royster, Royster & Killion, 1991; Emmerich, Rudel, and Richter. 2008) • Amplified musicians • PLD users have worse hearing thresholds than non-users (Meyer-Bisch, 1996, Kim et al, 2009) • Differences are typically small in teenagers 5
10/17/2018 Permanent effects of music • OAEs • “Heavy” PLD users have significantly lower OAE levels than non-users (LePage & Murray, 1998; Santollala Montoya et al, 2008) Tinnitus Significant tinnitus can reduce the ability to match pitch, control timbre Hyperacusis / recruitment Diplacusis 6
10/17/2018 “Notch” in audiogram Typically at 4000, 6000 Hz Notch definitions… No standardized definition of “notch” Research varies FREQUENCY IN HERTZ (Hz) 125 250 500 1000 2000 4000 8000 750 1500 3000 6000 KEY -10 R L 0 HEARING LEVEL (HL) IN DECIBELS (dB) AC (AIR) 10 UNMASKED 20 MASKED 30 BC (BONE) UNMASKED 40 MASKED 50 SOUND S FIELD 60 70 15 year old male 80 following right earwax removal daily PSS use “all the way up” 90 100 110 7
10/17/2018 FREQUENCY IN HERTZ (Hz) 125 250 500 1000 2000 4000 8000 750 1500 3000 6000 KEY -10 R L 0 HEARING LEVEL (HL) IN DECIBELS (dB) AC (AIR) 10 UNMASKED 20 MASKED 30 BC (BONE) UNMASKED 40 MASKED 50 SOUND S FIELD 60 70 14-year-old male (seen 4/09) Did not pass school hearing screen 80 Max volume on iPod, 60 min/day 90 100 110 120 DPOAEs, 14-year-old iPod users (1 ½ years), notched audiogram - Reduced or absent DPOAEs at frequencies 4000 Hz and above re: 95% normals (Gorga, et al., 1997) 8
10/17/2018 • 62 year old Cellist 62 year old flutist 9
10/17/2018 29 year old bassist – Intermittent use of HPDs, c/o tinnitus Distortion Product Otoacoustic Emissions Present & robust at 1500, 2000 Hz Present at low levels at 3000 Hz Absent 4000-10000 Hz 10
10/17/2018 Does a “Notch” mean NIHL? • Osei-Lah & Yeoh (2010) • 62 patients with “high-frequency notch” (39% of clinic patients) •40% had no history of noise exposure •25% bilateral, 50% left, 25% right • Must consider actual exposure • Unilateral vs. bilateral Damage risk criteria (DRC): - A model for understanding the dose-response relationship between noise and hearing loss. - Function of time of exposure and the level (dBA) of the exposure - “Acceptable” risk is a judgment call Population Fractiles of susceptibility: 0.1 0.5 0.9 “Tender” “Average” “Tough” (10% most) (10% least) 11
10/17/2018 NIOSH OSHA 85 dBA as an 8 hour 90 dBA as an 8 hour TWA TWA 5 dB exchange rate Exposures at or above this limit are hazardous Calculate: T(min) = 480/2^(L-85)/3 L = level, 3 = exchange rate • EU OSHA NIOSH – 80 dBA 90 dBA 85 dBA – 3 dB Exchange 5 dB Exchange 3 dB Exchange rate rate rate 80 dBA | 8 hrs 90 dBA | 8 hrs 85 dBA | 8 hrs 83 dBA | 4 hrs 95 dBA | 4 hrs 88 dBA | 4 hrs 86 dBA | 2 hrs 100 dBA | 2 hrs 91 dBA | 2 hrs 89 dBA | 1 hr 105 dBA | 1 hr 94 dBA | 1 hr CONSERVATIVE LIBERAL 12
10/17/2018 Damage-risk Criteria choice Organization 8hr Noise Exp Estimated % at Risk OSHA 90 dBA 21% 85 dBA 10% 80 dBA 3% NIOSH 90 dBA 29% 85 dBA 8% (NIOSH/EU) 80 dBA 3% 100% noise dose = 8 hours at recommended exposure level of a damage risk criteria NIOSH: 85 dBA for 8 hours = 100% dose 88 dBA for 4 hours = 100% dose 91 dBA for 2 hours = 100% dose Dose is cumulative 13
10/17/2018 So… what criteria do we use? • Damage-risk Criteria • OSHA (90 dBA, 5 dB exchange ratio) • NIOSH (85 dBA, 3 dB exchange ratio) • EU (80 dBA, 3 dB exchange ratio) • Percentage of noise dose? • 50% • 100% • Some other percentage? Who is at risk for MIHL • Musicians • Amplified musicians •Stage levels can exceed 110 dBA • Classical musicians •Levels may be lower, but exposure time is greater (200% dose per rehearsal) • Music students & teachers •Long exposure time 14
10/17/2018 Who is at risk for MIHL? • Listeners • Amplified music •Dance clubs •Concerts • Classical Music • Portable listening devices Mean Minimum Maximum Nightclub / discotheque 98 80 106 Personal cassette player 80 75 92 Rock / pop concert 104 80 120 Jazz concert 91 77 100 Symphony concert 90 80 100 15
10/17/2018 Does recreational exposure cause hearing loss? • It is difficult to show a causal relationship between recreational exposure and hearing loss • A noise notch is suggestive, not definitive • Only way to show cause is to document exposure Musicians Support staff Workers exposed to music In music-filled environments Their own PLDs 16
10/17/2018 Output Levels of PLDs Music players can produce high outputs levels 70% = 83 dB 80% = 89 dB 90% = 95 dB 100% = 101 dB 17
10/17/2018 Portnuff, Fligor & Arehart (2011) 18
10/17/2018 European Union OSHA NIOSH 80 dBA 90 dBA 85 dBA 3 dB Exchange 5 dB Exchange 3 dB Exchange rate rate rate 80 dBA | 8 hrs 90 dBA | 8 hrs 85 dBA | 8 hrs 83 dBA | 4 hrs 95 dBA | 4 hrs 88 dBA | 4 hrs 86 dBA | 2 hrs 100 dBA | 2 hrs 91 dBA | 2 hrs 89 dBA | 1 hr 105 dBA | 1 hr 94 dBA | 1 hr CONSERVATIVE LIBERAL Damage-risk Criteria 90 dBA, 5 dB exchange ratio (OSHA) 85 dBA, 3 dB exchange ratio (NIOSH) 80 dBA, 3 dB exchange ratio (WHO) Percentage of noise dose due to music? 50% 100% Some other percentage? 19
10/17/2018 Listening Time Guidelines • As people are exposed to more than just their MP3 player… time to 50% noise dose NOTE: Do NOT over-interpret this table to suggest “isolator” headphones are more dangerous! Listening Behavior 20
10/17/2018 110 100 Chosen listening level (dBA) 90 80 70 60 50 10 20 30 40 50 60 70 80 90 Background noise (dBA) Portnuff, unpublished dissertation (2011) CLLs and SNR Noise Mean CLL (Std. Dev) Mean SNR (Std. % of listeners Dev) >85 dBA Quiet 74.1 dBA (14.2 dBA) 25% 50 dB 76.0 dBA (12.2 dBA) 30.5 dB (12.7 dB) 23.1% 60 dB 82.0 dBA (10.3 dBA) 24.7 dB (10.9 dB) 28.9% 70 dB 87.0 dBA (9.0 dBA) 19.7 dB (9.5 dB) 53.9% 80 dB 93.1 dBA (7.8 dBA) 15.8 dB (7.9 dB) 84.6% Portnuff, unpublished dissertation research 21
10/17/2018 Manikin measures in public places Study % of subjects Location exceeding 100% noise dose (NIOSH) Levey, Levey & Fligor (2011) 51.9% Urban university campus, New York City, NY Williams (2005) 25% Busy streets, Melbourne and Sydney, Australia Williams (2009) 17% Busy streets, Brisbane, Canberra, Australia Keith et al (2011) 3.2% Quiet classrooms, Ottawa, ON Epstein, Marozeau & 0% Various locations, Boston MA Cleveland (2010) 22
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