Personal Music Players: Are We Measuring the Sound Levels Correctly?

TLDR: The purpose of this article is to provide a factual basis to assess the potential risks of PMP use by offering guidance on how audiologists can accurately measure PMP sound levels to estimate realistically the risk of hearing damage.

Abstract: W ith the introduction of the Walkman by Sony in the late 1970s, personal music listening habits were forever changed, only to be supercharged early in this century by Apple’s iPod players. The proliferation of personal music players (PMPs) is a cultural change that raises concern because of the tremendous quantity of audio stimulation that users—especially children— can now regularly introduce to their ears. Much has been reported about the use of PMPs in the scienti c and trade literature as well as in the popular media. A Google search for the 12 months from January 2008 to January 2009 for the terms “warning music ‘hearing loss’” yielded 19,000 hits. Although a number of these hits represented measured information and advice, many included dire predictions such as this 2009 headline from News. Com.Au: “Experts warn of MP3 player hearing loss ‘catastrophe.’” The purpose of this article is to provide a factual basis to assess the potential risks of PMP use by offering guidance on how audiologists can accurately measure PMP sound levels to estimate realistically the risk of hearing damage. The sidebar and Figure 1 on page 15 summarize the potential risks of PMP use relative to other noisy activities for young people. Regardless of whether an audiologist chooses to measure earphone outputs, it is important to understand the relative risk of music listening so that clients may be counseled appropriately. Although PMPs may not be the bane of young people’s hearing, these devices can be played too loudly, too long, and too often. Indeed, studies indicate that most of these devices are capable of producing high sound levels (Fligor & Cox, 2004; Keith et al., 2008; Portnuff & Fligor, 2006). Investigations of typical PMP listening levels suggest that most users adhere to safe levels, although there is evidence that a small percentage do not. Some young people (estimates vary widely) play PMPs at sound levels of 85 dBA or greater especially when background noise is present, using higher volume settings with louder background noise (Airo et al., 1996; Fligor & Ives, 2006; Portnuff et al., 2009). One mitigating factor in the presence of background noise is earphone type. Listeners tend to choose lower output levels in noisy environments when using sound-isolating earphones (Fligor & Ives, 2006). Only a handful of studies have attempted to factor in PMP use times, which are needed to estimate eight-hour equivalent average exposures. These results suggest that about 15% to perhaps as many as 25% of users would be expected to have exposures equal to or exceeding 85 dBA on an occasional or routine basis (Airo et al., 1996; Portnuff et al., 2009; Williams, 2005). Of concern is that the rate of PMP use is on the rise. Average listening time has increased over the past 20 years, from about 40 minutes per day in the 1980s to an hour per day in the 1990s to two hours per day in this decade (Ahmed et al., 2006; Airo et al., 1996; Bradley et al., 1987; Felchlin et al., 1998; PasschierVermeer, 1999; Rice, Rossi, & Olina, 1987; Torre, 2008; Williams, 2005). Although hearing risk from PMPs may not be a widespread public health concern, further research is underway. It is important for hearing professionals to identify those individuals who are at risk by accurately measuring PMP sound levels to assess more sensibly the likelihood of hearing damage.