Sports – the American pass time. We all love to root on our home teams regardless of the season. And if we are lucky, we get to see our teams live on the field or on the court at the local arena. The atmosphere is electric, the competition fierce and the crowd noise is deafening.
We often hear about a competitive or home field advantage which allows home teams the ability to manipulate sound levels via fan participation and even through artificial noise generated from arena stereo and speaker systems. You’ve all experienced “Let’s get ready to rumble” with the lights and pumped up music. However, the competitive advantage of these extreme noise levels comes at a cost. In fact, noise levels can be comparable to that of a jet engine or a chainsaw — high enough to potentially cause short- or long-term damage to one’s hearing and alter the structural and functional anatomy responsible for hearing.
The assault on the ear
Excessive noise can cause both temporary and permanent injury to the ear, determined by the level and duration of sound. Damage to ear structures following a traumatic exposure can manifest in hair cells and the organ of Corti, which contains the hair cells. The mechanism of damage varies from structure to structure. Loss of hair cells is generally due to cell death that occurs because of the stress placed on hair cells during a traumatic sound exposure.
Thankfully, humans are born with as many as 3,500 inner hair cells and 12,000 outer hair cells for a total of more than 15,000. This number allows people some buffer for exposure to loud noise, but the total can quickly diminish, as these cells do not repopulate themselves. As an increasing number of cells die, the ability to perceive sound decreases. Therefore, a single loud sound or time in a noisy arena may not cause noticeable differences in hearing right away, but as the number of exposures or the length of exposure to traumatic sound levels increases, so will the number of hair cells that die. This can lead to increased thresholds for sound or decreased hearing.
While loss of hair cells is the primary cause of noise-induced hearing loss (NIHL), damage to the organ of Corti is another potential cause. Like hair cells, organ of Corti damage can occur because of a single exposure to very loud sound or long-term exposure to excessive noise. Single exposures to decibel levels greater than 130 decibels (dB) can cause the organ of Corti to dissociate from the basilar membrane. Similar to the mechanism of hair cell damage, this dissociation disrupts signaling from reaching the intended nerve, therefore decreasing the perception of sound.
Not only are fans at risk but consider the players and officials who are regularly exposed to these excessive noise conditions as part of their daily jobs. In the United States, 23% of noise exposed workers suffer from some form of hearing loss. While the rates of hearing loss have not been completely examined for athletes and officials, it is probable they experience the same level of hearing damage due to the thresholds that are in place for acute and prolonged noise exposure over the course of a season and career.
What’s your best hearing defense at the game?
The good news is that NIHL is a preventable form of hearing loss that can be addressed by controlling your exposure to unsafe noise levels. Occupational Safety and Health Administration (OSHA) criteria define hazardous noise conditions at 85 dB over an 8-hour period. A Murray State University study examined noise levels in their mid-size NCAA basketball arena holding on average 8,700 fans. The results showed peak noise levels of greater than 130 dB in each of the three games studied. Certainly, well over the safe noise exposure threshold.
We know that avoidance is the obvious best defense against NIHL. Yet there will always be the draw to the big game. Here is what you can do to put on a good defense:
- Be aware – start by knowing when noise levels exceed safe thresholds. You can download a decibel meter on your smartphone to know when loud is too loud.
- Wear ear protection – simply using ear plugs can decrease the level of exposure depending on the Noise Reduction Rating (NRR). For example, an NRR of 26 can block out a maximum of 26 dBs if perfectly fitted and inserted correctly. A good rule of thumb is you would have a reduction of 13 dB, or about 50% of the rating to allow for variances in proper fit and insertion. Additional protection may be received from the over the ear muffs often seen at auto races and on young children.
- Limit exposure – consider enjoying the game in comfort of your living room where you control the crowd noise. Remember to keep the volume turned down on the TV or radio.
So, go ahead and keep rooting for the home team, but remember to take along your best defense against crowd noise. If you are a super fan and suspect you may already have noise induced hearing loss, we recommend you set an appointment to get evaluated.