Turn Down For What?!
Hearing is one of the most important human senses, empowering us to connect socially and live safely within our surroundings. The ability to hear is a basic communication need, and for dancers it is essential to interpret the cues of music clearly with each step on the stage. Understanding rhythm and interpreting melodies are key components of choreographing a piece and coordinating dancers in a group to bring movements alive. As energy levels rise throughout dance competitions and recitals often the volume of the music peaks as well. Sometimes it becomes what we can only describe as LOUD. But at what point is this cause a concern? Can the exposure of loud music have long-term implications for dancers and their audiences?
Well, the short answer is yes, and in fact noise-induced hearing loss is the leading preventable cause of permanent hearing impairment. In fact, a report from a large-scale American national health survey indicated that 12% to 15% of school-aged children have some hearing deficits attributable to noise exposure1. While there are not yet any similar studies in Canada, statistics do suggest that 13% of children 14 years and younger have some type of hearing disability2.
In a healthy ear, the tiny and delicate cells of the inner ear, known as the hair cells, actually wiggle and dance when stimulated by sounds. By contrast, after those hair cells are exposed to loud noises they may stop moving altogether and crumple down as a dancer would in the dramatic conclusion of an interpretive dance. Hair cells cannot always repair themselves, nor can they regenerate, which leads to a permanent hearing loss. Hearing impairment due to noise exposure usually happens gradually over time and not all individuals exposed to loud noise will experience the same damage, with genetics and other health factors playing a contributing role. Unfortunately we cannot measure how many cells are damaged with each exposure, and this exposure does add up over time posing a risk to ears of any age. Hearing loss may range in severity from mild to profound, but any hearing handicap for a child can have significant consequences when it comes to learning at school, making new friends, and considering future life plans.
And hearing loss is not the only risk of loud noise exposure: another unwelcomed side effect can be the onset of tinnitus, the perception of ringing or buzzing in one’s ears, where no sounds are actually present. As a dancer, dance teacher, dance parent or audience member, you have probably experienced these annoying sounds at least once after spending time close loud music, and wondered what that noise was and what it meant. Well, that was a warning being cried out from the hair cells of your ears, letting you know that the environment you were in was much too loud! But exactly how loud is too loud?
Loudness is measured in decibels, a logarhythmic scale of sound levels abbreviated as “dB”. To give some perspective, most sounds below 0 dB are completely inaudible to humans, whereas 120 dB is about the threshold of pain, and 65 dB is the approximate speaking volume of an average voice. So where in this range does exposure become dangerous? Well, there are three aspects to consider: 1) How loud is the sound? 2) How close are you to that sound? and 3) How long are you exposed to that sound for? First, if a sound is perceived to be painfully loud, then that is a definite sign that it is able to cause damage to the inner ear. And even exposure to noises much lower in level can impair hearing as
well, particularly with repeated subjection. For example, a typical vacuum cleaner would emit noise around 85 dB, which may pose a threat if you are next to that vacuum cleaner all day every day. The Canadian federal noise regulations state that the maximum permitted exposure level of continuous noise is a workplace if 87 dB for 8 hours3. In Ontario workplaces, sound levels greater that 85 dB generally require hearing protection devices, warning signs and reduced exposure times. The sound levels are generally measured using calibrated sound level meters, however there are free apps available for smart phones that can an estimated measure of dBs in a given environment. These approximations could be helpful for bringing awareness to just how loud the music is at a dance competitions or recitals, and to determine when it may be unsafe.
To protect your hearing, a simple suggestion is to stay at a distance from the music source whenever possible. As I mentioned earlier, the proximity to the source of the sound plays a factor, and the ultimate example of this is a personal listening device, such as an mp3 player with headphones, which put the speakers directly into the ears. These devices allow children to listen to music for hours at a time and are a growing concern for a child’s hearing health. Furthermore, a common tendency is to turn the volume up on personal device to overcome noisey environments, such as a bus trip or backstage at a recital. These situations may lead the listener to misjudge the volume and turn it up louder than they would normally perceive to be appropriate. A practical solution to this is to restrict the maximum volume output setting on the listening device. It may also be helpful for parents to help their children decide what level sounds appropriate in a quiet environment and educate them about why it is so important to avoid increasing the volume beyond that point. Finally, for the dancer wanting to listen to his/her iPod on repeat, taking breaks from the device every 15 minutes would help the inner ear to avoid unnecessary stress.
Of course distancing oneself from loud environments is not always possible, nor desirable. In these situations, investing in proper hearing protection for the ears can be a great option. Disposable foam plugs are an easy and cost-effective option for dampening sound, but often difficult to fit inside small ears. For this reason, the most common choice for babies and toddlers is the over the ear “muffs”. Custom-made plugs are moulded unique to each ear and can be more ideal for older children, though a more costly option. For the dancer or musician looking to dampen sound without sacrificing the clarity of acoustic cues, advanced acoustic plugs can be customized with filters for preserving sound quality at a desired level. We must however caution that while these plugs are great for protection for loud noise, the overuse of such plugs should be avoided, as regular access to environmental sounds are essential for normal development in children.
In summary, the sense of hearing is precious, especially to dancers, and noise-induced hearing loss is completely preventable for everyone. The suggestions above give some tips for protecting children’s hearing health in dance environments to avoid noise-related hearing disorders. If you suspect your dancer, child or someone that you love is not hearing as well as they used to, please seek medical attention from a health care professional, such as Audiologist who can complete a full hearing assessment and make further recommendations.