Noise-induced hearing loss (NIHL) is not limited to army veterans, individuals who work in noisy environments, or musicians. It can also happen to individuals who recreationally listen to music loudly. NIHL can be caused by a single, loud explosion, or by continuous exposure to loud sounds over a long time. An example of such this would be listening to loud music when driving.

What is too loud?

To provide context, it’s important to note that 60dB is the volume of an average conversation. Most research has advised individuals to refrain from exposure to sounds louder than 85dB. The loudness of the sound is not the only factor to keep in mind, but also for how long you will be exposed to the sound and how closely. 85dB is regarded as the maximum volume you can listen to for eight hours without harming your hearing. However, the amount of decibels and duration of exposure to the sound source does not have a linear relationship.

According to the Centers for Disease Control and Prevention (CDC) for every 3dB increase of sound, the safe exposure time is cut in half. This suggests that a sound at 88dB can only be listened to safely for four hours. Many drivers find themselves turning up their car stereo to mask out any sounds from heavy traffic on the highway, which can range from 70-80dB or more as motorbikes can reach a sound level of 80-100dB. Depending on the car’s sound system it could reach a maximum of 110dB or more. This is especially dangerous considering the proximity the driver and the sound source.

Your sound system is too loud if you are unable to hear any oncoming police vehicle, fire truck, or ambulance as the siren alone reaches 110-120dB. At that sound level in your car, you are directly endangering your hearing as safe exposure time is practically limited to seconds.

How does a loud car stereo affect your hearing?

The ear consists of very delicate hearing organs. Noise is harmful to hearing because it damages the tiny hair cells in the cochlea responsible for processing and sending electrical sound signals through the auditory nerve to the brain. When these tiny hair cells, known as stereocilia, endure extended periods of exposure to hazardous levels of noise the vibrations from the noise can be so powerful that they damage the hair cells permanently. When these hair cells are damaged they cannot regrow and are irreplaceable.

It is important to note that NIHL can temporarily cause reduced hearing as well as permanent sensorineural hearing loss. An acute temporary NIHL is quite common, but repeated exposure to loud situations can cause this temporary threshold shift, therefore noise must be kept to a minimum. If not – it may lead to a permanent hearing loss. Some examples of listening situations that can cause an acute temporary NIHL include: loud concerts; going to a shooting range without any hearing protection gear; being close to an explosion; or listening to your car stereo during your morning and afternoon work commute with the volume turned up to more than 95dB to 100dB. After taking part in any of these activities sounds may seem far away, muffled, and you may experience a ringing sound in your ear. The temporary decrease in hearing may disappear after 16 to 48 hours, but research has shown that there may be residual long-term damage to your hearing.

Early signs and symptoms of NIHL

If you have been exposed to very loud noise, such as some of the examples provided above, you should monitor your hearing and consult a hearing expert if your hearing has not recovered from the temporary threshold shift. Signs that may indicate a need for further hearing testing include:

• You have pain in your ears after being exposed to loud noise.
• You can hear sounds, but you find yourself struggling to understand what your friends and family are saying. You feel as though they are “mumbling” during conversations.
• You have recently started to experience a ringing, whooshing, buzzing, humming, roaring, or whistling sound in your ear. This is known as tinnitus.
• People mention that you are setting the volume of the television, stereo, or radio too loudly.

Other disadvantages of loud car stereos

Loud music can decrease a driver’s overall awareness of his/her surroundings on the road. As a driver you cannot rely solely on your sight to determine whether or not there is danger on the road – we must also be able to hear. The most important example is being able to hear sirens to know when an emergency vehicle is approaching.
Some research has suggested that a driver’s reaction time can decrease by 20% when listening to music. That percentage was found when a car stereo was at 95dB, which is equal to the loudness level of some lawnmowers and motorbikes. Reaction time depends on many human factors, but if you are distracted by your music you may respond slower to the driver in front of you when they decelerate.

How to prevent damage to your hearing

Prevention starts with education, and it is important to be aware and informed about warning signs that a sound may be damaging your hearing and to remove yourself from these noisy listening situations. Remember a sound may be harmful and exceed 85dB, if:

• The sound makes your ears hurt,
• Your ears start to buzz or ring after being exposed to the sound,
• You need to raise your voice during conversations to talk over the sound,
• After leaving the listening situation your ears feel “blocked”, other sounds appear to be “muffled”, or your friends seem to be “mumbling”.

We hope this article has been informative and educational and that you feel empowered to protect your hearing from noise and reduce unnecessary harm to your hearing. We encourage you to consult with a hearing healthcare professional or one of our Lexie Experts if you have any other questions, or concerns, regarding your current hearing experience.