Why are fire alarms so loud?

You've probably been to a concert, listened to the sound of a fighter plane, or passed by a jackhammer on a construction site. People avoid loud environments because it can cause hearing loss in the future.

This raises the question: Why are fire alarms so loud? Is there anything you can do for your ears to be protected from the noise?

How loud are fire alarms?

NFPA 72 outlines requirements for fire alarm notification devices, which can take two forms: audible or visible.

• Sirens and horns sound the alarm, sounding at 65 to 120 decibels (dB). are less than 10 feet away from the device.
• The visible alert is provided by the stave lights, which flash once per second at 15 to 1000 candelas depending on the setting.

It is clear that repeated and prolonged exposure to loud noises can cause hearing loss. According to the National Institute on Deafness and Other Communication Disorders, 85dB or greater is considered the highest risk zone for hearing loss.

These noise examples will help you to understand the decibel levels of various decibels.

• Indoor conversation: 50 dB
• The chatter in restaurants: 60 dB
• Vacuum cleaner: 70 dB
• Garbage disposal and food blender: 80 to 90% dB
• Power lawn mowers and motorcycle engines: 100 dB
• Thunderclap: 120dB
• Take-off at 25m: 150 dB (eardrums could rupture if exposed for too long without protection).

Why do fire alarm volumes vary?

Fire alarms are designed to notify everyone within the building to evacuate. The NFPA mandates that fire alarm sirens and horns sound louder than the ambient noises.

The exact requirement is 15 dB above average noise level or 5dB higher than the maximum ambient sound. However, an industrial setting with loud equipment might need to have the alarm sound closer to 120dB to make sure the sound stands out from the surrounding noises.

Fire alarms require a high volume level due to the fact that the sound is perceived less loud if it is further away. Also, noise absorption in building materials can be a problem, particularly if doors are closed between rooms. These factors mean that the decibel level must reach the source in order to ensure that the sound travels to all corners of the building.

How can you protect your ears from loud fire alarms?

Cover your ears immediately you hear the alarm sound. It is a good way to protect your hearing while you move calmly towards the exit and make your escape.

Importantly, you should create a fire evacuation plan, and conduct regular fire drills. Your staff will be able to confidently plan what to do and where to go in an emergency. Planning ahead can reduce confusion and the amount of time you are exposed to loud sounds.

If you feel that your fire alarm's decibel level is too high, it is worth hiring a professional fire protection company to inspect your equipment and make a determination. Your technician will ensure that the volume is safe and compliant with NFPA 72.

Fire alarms are loud and must not be tampered with. The NFPA established fire codes to ensure maximum safety in buildings across all industries. Non-compliance penalties could include increased liability and fines for disconnecting or adjusting your fire alarm sirens.