Personal music systems may be hazardous to hearing

shutterstock_290230064

Improvements in digital technology have meant that an increasing number of people are listening to music via personal music systems such as MP3 players and mobile phones for prolonged periods of time. These music systems are increasingly small and lightweight with considerable storage capacity and improved sound quality – which has led to prolonged use at higher volume settings, particularly among young people.

A paper published in The Journal of Laryngology & Otology (JLO) finds, alarmingly, that large proportions of young adults are listening to personal music systems at levels higher than safety levels recommended by regulatory bodies. The study finds that listening to music through personal music systems at high volume through ear phones or ear buds may be potentially hazardous to hearing.

The paper’s co-authors – from the All India Institute of Speech and Hearing in Mysore, South India – recruited 60 participants between the ages of 15 and 30 years old for their study, which looked at regular users of personal music systems and non-users of personal music systems. The researchers also used manikins to measure the output of sound pressure levels of personal music systems.

Supported by India’s Department of Science and Technology, the study found that an alarming proportion of young adults were using personal music systems at levels that could potentially damage their hearing. The study found that people who listened to personal music systems at levels higher than 80 decibels had significantly poorer hearing thresholds in high frequencies when compared to other participants. The preferred range for listening to music among participants was 51 to 98 decibels – while workplace noise regulation in the UK, for example, limits the daily exposure levels to 80 decibels.

The study also found that 33 per cent of participants reached the maximum allowable noise level after listening to music for more than four hours, while 20 per cent reached the limit within one hour – with 30 per cent of used personal music systems at levels higher than the permissible limit.

People who listened to personal music systems at levels higher than 80 decibels also showed significant difficulty in perceiving speech in adverse listening conditions, compared to other participants in the study. The authors suggest that this reduced function may be linked to damage to the cochlear structure.

However, all the participants in the study had normal hearing in the conventional frequency range, the study found.

“Our results suggest that listening to music through personal music systems at higher volume levels (over 80 dB LAeq) may not result in clinically significant hearing loss, yet may cause subtle pre-clinical damage to the auditory system, and over the years such behaviour may be hazardous to hearing,” the authors conclude.

The full paper, published in The Journal of Laryngology & Otology, “Personal music systems and hearing” by U A Kumar and S R Deepashree, can be viewed free of charge until 31 August 2016 here.

Turn down the Volume? An examination of the effects of nightclubs on hearing

dj

There is a growing body of evidence that suggests excessive noise levels in nightclubs have an adverse effect on hearing, and may ultimately be responsible for noise-induced hearing loss.

A study by researchers at the University of Birmingham found that although students didn’t want to alter their attendance, the majority would rather see noise limits reduced to safe limits, contrary to the widely held preconception that high volume levels in nightclubs are demanded by young people.

The hearing of all employees in the music and entertainment sector is now protected by The Control of Noise at Work Regulations (2005), which require employers to prevent or reduce risks to employees’ hearing in the workplace when exposed to noise levels above 85 dB. However, this law does not apply to members of the public attending nightclubs, as it is presumed they are making an informed decision to attend such venues.

This study investigated the prevalence of symptoms related to noise-induced hearing loss that were experienced by students after attending nightclubs. It also aimed to explore students’ awareness of the association between noise-induced hearing loss and nightclub attendance, and examine their attitudes towards this.

A questionnaire was distributed to students entering or leaving the University of Birmingham Medical School over a 5-day period during March 2012, with a total of 357 individuals completing the questionnaire, with almost half the students attending a nightclub at least once per week.

Of those students surveyed in the present study (excluding those who never attended nightclubs and those with pre-existing hearing problems), 88% had experienced transient tinnitus after attending a nightclub. This finding is important because transient tinnitus can also be a precursor to other noise-induced hearing loss symptoms, including permanent tinnitus, hyperacusis or irreversible hearing loss.

The majority of students in the sample population (90%) were aware that current nightclub noise levels are potentially damaging to hearing. However, most students who attended nightclubs (73%) reported that they would not alter their attendance, despite being told that the noise levels could lead to permanent hearing loss. Nonetheless, 70% of nightclub attendees agreed that noise levels should be limited to volumes that are not damaging to hearing.

Mr Oliver Johnson, one of the paper’s authors, commented. “This is encouraging for policy makers, as noise levels could potentially be lowered below the threshold for hearing damage without nightclub attendance being significantly compromised. The implementation of relevant legislation could therefore potentially reduce the long-term risks of irreversible hearing loss in this young age group without damaging the nightclub industry.”

The study also demonstrated that 87% of students with normal hearing had never received information about noise-induced hearing loss or had earplugs recommended in the nightclub setting. The findings and those of other research groups indicate that young people attending nightclubs are at high risk of noise-induced hearing loss, and it is therefore of the utmost importance that they should be provided with adequate information regarding the potential damage that excessive music levels in nightclubs may cause.

Mr Johnson added, “We believe the current assumption implied by legislation, namely that nightclub attendees are consenting to the risks of hearing damage, is spurious, as the majority of young people in nightclubs are likely to be unaware of these risks.”

The full paper “British university students’ attitudes towards noise-induced hearing loss caused by nightclub attendance” is published in The Journal of Laryngology & Otology and can be read free of charge for a limited time here.

Is Blu-tack as effective at attenuating sound as over-the-counter ear plugs?

ear plugsA new study has revealed that using Blu-tack to protect the ears can be as effective as inserting custom-made, shop-bought earplugs from Boots and Aearo.

Researchers from the University Hospital of South Manchester and the Withington Community Hospital have reported their findings in The Journal of Laryngology & Otology. They conclude that Blu-tack – a non-toxic adhesive putty produced by Bostik since the 1970s – is a ‘comfortable alternative to over-the-counter ear plugs for the attenuation of everyday sound.’

Numerous means of hearing protection are available to prevent the negative physiological and psychological effects that can be caused by the noise we are exposed to on a daily basis. Designed to be ‘affordable, comfortable, and disposable’, they aim to attenuate mid to high frequency sounds by 20-30 dB. They are usually made from foam, putty, wax, and silicone polymers and can be purchased at most pharmacies. Blu-tack can now be counted as an additional option when it comes to defending against noise.

The idea for the investigation came from main author G J Watson who, when using Blu-tack to prevent water from entering the ears following the insertion of ventilation tubes, noticed that it attenuated sound.

Nineteen volunteers participated in the study. They were provided with E-A-Rsoft disposable yellow foam plugs (Aearo), Boots Muffles wax ear plugs, Boots Flight ear plugs, and Blu-tack. Their hearing thresholds were assessed before and after the insertion of the ear plugs at 0.5, 1, 2, 3, 4, 6 and 8 kHz. The results were compared with hearing thresholds after the insertion of Blu-tack.

Volunteers were also asked to assess how easy to insert the ear plugs and Blu-tack were, how comfortable they were, and how much peace of mind they offered.

Blu-tack was not as effective as the ear plugs at attenuating sound at low frequencies, but performed as well as the ear plugs at frequencies over 3 kHz. And, perhaps surprisingly, Blu-tack was rated as significantly more comfortable to wear. Participants found that Blu-tack was as easy to insert as the ear-plugs, and offered them the same peace of mind.

The authors conclude that Blu-tack is

as effective as over-the-counter ear plugs at attenuating frequencies above 3 kHz. It was considered comfortable and safe to use and could therefore be regarded as an alternative option when wishing to attenuate everyday sound.

The full paper is available free for a limited time via the following link:

Journals.cambridge.org/JLO/blutack

%d bloggers like this: