Health <strong>risks</strong> <strong>from</strong> <strong>exposure</strong> <strong>to</strong> <strong>noise</strong> <strong>from</strong> <strong>personal</strong> <strong>music</strong> playersABSTRACTExposure <strong>to</strong> excessive <strong>noise</strong> is a major cause <strong>of</strong> hearing disorders worldwide. It isattributed <strong>to</strong> occupational <strong>noise</strong>. Besides <strong>noise</strong> at workplaces, which may contribute <strong>to</strong>16% <strong>of</strong> the disabling hearing loss in adults, loud sounds at leisure times may reachexcessive levels for instance in discos and <strong>personal</strong> <strong>music</strong> players (PMPs). It is estimatedthat over two decades the numbers <strong>of</strong> young people with social <strong>noise</strong> <strong>exposure</strong> hastripled (<strong>to</strong> around 19%) since the early 1980s, whilst occupational <strong>noise</strong> had decreased.The increase in unit sales <strong>of</strong> portable audio devices including MP3 has been phenomenalin the EU over the last four years. Estimated units sales ranged between 184-246 millionfor all portable audio devices and between 124-165 million for MP3 players.Noise-induced hearing loss is a function <strong>of</strong> sound level and duration <strong>of</strong> <strong>exposure</strong>. In order<strong>to</strong> counteract <strong>noise</strong>-induced hearing loss more effectively, a European directive “Noise atWork Regulations” taking effect starting February 2006, established the minimal securitylevel at the equivalent <strong>noise</strong> <strong>exposure</strong> limit <strong>to</strong> 80 dB(A) for an 8 hour working day (or 40hour working week), assuming that below this level the risk <strong>to</strong> hearing is negligible. The8-hour equivalent level (L equ, 8h ) is a widely used measure for the risk <strong>of</strong> hearing damagein industry, and can equally be applied <strong>to</strong> leisure <strong>noise</strong> <strong>exposure</strong>s. The free-fieldequivalent sound pressure levels measured at maximum volume control setting <strong>of</strong> PMPsrange around 80-115 dB(A) across different devices, and differences between differenttypes <strong>of</strong> ear-phones may modify this level by up <strong>to</strong> 7-9 dB. The mean time <strong>of</strong> <strong>exposure</strong>ranges <strong>from</strong> below 1 hour <strong>to</strong> 14 hours a week.Considering the daily (or weekly) time spent on listening <strong>to</strong> <strong>music</strong> through PMPs andtypical volume control settings it has been estimated that the average, A-weighted, eighthour equivalent sound <strong>exposure</strong>s levels (referred <strong>to</strong> “Noise at Work Regulations”) <strong>from</strong>PMPs typically range <strong>from</strong> 75 <strong>to</strong> 85 dB(A). Such levels produce minimal risk <strong>of</strong> hearingimpairment for the majority <strong>of</strong> PMP users. However, approximately 5% <strong>to</strong> 10% <strong>of</strong> thelisteners are at high risk due <strong>to</strong> the levels patterns and duration <strong>of</strong> their listeningpreferences. The best estimate <strong>from</strong> the limited data we have available suggests that thismaybe between 2.5 and 10 million people in EU. Those are the individuals listening <strong>to</strong><strong>music</strong> over 1 hour a day at high volume control setting.Excessive <strong>noise</strong> can damage several cell types in the ear and lead <strong>to</strong> tinnitus, temporaryor permanent hearing loss (deafness). Published data indicate that excessive acute<strong>exposure</strong>s <strong>to</strong> PMPs <strong>music</strong> at maximal or near maximal output volume can producetemporary and reversible hearing impairment (tinnitus and slight deafness). Majordiscrepancies exist between the results <strong>of</strong> the studies on permanent <strong>noise</strong>-inducedhearing loss in PMP users, with both, positive and negative studies published. Tinnitusand hearing fatigue may occur more frequently in teenagers chronically exposed <strong>to</strong><strong>music</strong>, including PMP users, than in non-users.In addition <strong>to</strong> audi<strong>to</strong>ry effects harmful, lasting and irreversible non-audi<strong>to</strong>ry effects <strong>of</strong>excessive listening <strong>to</strong> PMP can be expected; they include cardiovascular effects, cognitionas well as distraction and masking effects. However, there is not sufficient evidence <strong>to</strong>state that <strong>music</strong> <strong>from</strong> PMPs constitutes a risk for such effects.In the face <strong>of</strong> an increasing population at risk <strong>of</strong> hearing loss and tinnitus due <strong>to</strong> i)increasing PMPs use and acceptance in the EU and ii) the possibility <strong>to</strong> use PMPs at highsound levels, there is a lack <strong>of</strong> data concerning:a) the current PMP use pattern, duration, output level, choice <strong>of</strong> loud levels and <strong>exposure</strong><strong>of</strong> users <strong>to</strong> other high level sound sources.b) the contribution <strong>of</strong> loud sounds <strong>to</strong> hearing loss and tinnitus, as well as cognitive andattention deficits in children and young people.c) long-term studies using more sensitive hearing impairment measures <strong>to</strong> assess theimpact <strong>of</strong> PMPs on hearing and <strong>to</strong> identify the potential sub-groups more ‘at risk’ (e.g.4
Health <strong>risks</strong> <strong>from</strong> <strong>exposure</strong> <strong>to</strong> <strong>noise</strong> <strong>from</strong> <strong>personal</strong> <strong>music</strong> playerschildren, genetic sub-groups and environmental sub-groups such as those who commute<strong>to</strong> work or school in noisy surroundings).d) biological basis <strong>of</strong> individual susceptibility <strong>to</strong> <strong>noise</strong> and the benefits <strong>from</strong>pharmacological treatment.e) whether excessive voluntary PMP-listening leads <strong>to</strong> lasting and irreversible cognitiveand attention deficits after the cessation <strong>of</strong> the <strong>noise</strong>.Keywords : Health effects, Noise, Noise Induced Hearing Loss, Personal Music Players,SCENIHROpinion <strong>to</strong> be cited as : SCENIHR (Scientific Committee on Emerging and Newly-Identified Health Risks), Scientific opinion on the <strong>Potential</strong> <strong>health</strong> <strong>risks</strong> <strong>of</strong> <strong>exposure</strong> <strong>to</strong><strong>noise</strong> <strong>from</strong> <strong>personal</strong> <strong>music</strong> players and mobile phones including a <strong>music</strong> playing function,23 September 2008.5
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