Sirens are but one of the more conspicuous noises of city living. Especially the part of the city my husband and I live in. Our condominium building sits very close to the intersection of Jalan Tun Razak and Jalan Ampang, two long and traffic busy roads in Kuala Lumpur. There are 3 hospitals on our left. One on the right. Two along the top of the road. There is also a fire station and a police station nearby. Handy.

We both like where we live. It’s been our home for over a decade now. The magnificent views of the city skyline, and proximity to so many iconic sites such as the Petronas Twin Towers, the KL Tower, the Saloma Link Bridge and The Exchange TRX make it worthwhile. Plus, the easy to walk to restaurants, clubs, shopping malls and LRTs and MRTs, once the latter is built. No driving. No parking hassles.

Downsides. The big 3. Noise. People. Heat. All 3 can be annoying but they are fairly manageable. Noise – we have double glazed windows and we keep our doors closed. People – we avoid busy places as much as possible. Heat – air conditioning at home.

I only became more aware of the wails of sirens and revving of motorbikes after I moved in with my mum. She lives on a lower floor and her windows and sliding door are not reinforced. There was no need to as my mum is quite deaf and doesn’t hear much. Worse now, after she abandoned her hearing aid.

Back to the sirens. I wondered why emergency vehicles pitched their sirens so loud, especially at night, when the roads are generally clear of traffic. Regulations. Policies. Necessity. Financial liability. And, primarily to alert all and sundry on the road. For instance, to warn vehicles that might suddenly appear from a side road or pull out of a parking bay and not yield or give way to emergency vehicles. To announce to pedestrians, who might contemplate crossing the road because it appears to be vehicle-free. It just takes one other vehicle and/or one other person to cause a collision. And, delay treatment or save someone’s life in a fire or a burglary.

But, why so loud even during the day? Again, to capture the attention of road users. The sirens must be heard inside vehicles that usually have their windows closed, and above the distraction and dings of mobile phones, music and conversation with fellow passengers. Plus, at enough of a distance for drivers to react safely. Not brake abruptly but slow down, and give way to emergency vehicles.

“Some fail to yield because they are unaware, some out of a lack of understanding of what they should do, others by underestimating the importance or (at least from the look of it) not caring. The vehicles are traveling with lights and siren because the matter is important enough for the drivers to value haste over an increased risk to their own safety and others. Driving lights-and-siren may be common, but it is never done lightly[1].”

How loud is loud? “Sirens from a fire truck, a police car or ambulance measure between 110-129dB or decibels. A decibel is a unit of sound intensity. To get a better idea, our normal talking voice at arm’s length is 65-80dB. Listening to very loud music with headphones is 96-110dB. While firecrackers and fireworks are a painful 140-160dB[2].”

Sirens are loud, just based on the short bursts of exposure, in my home and in my car. Inconsiderately, I never considered this. How loud sirens are to emergency vehicle drivers and riders who are exposed to it all the time. “Long term use of sirens is damaging … and obviously will affect the drivers of the emergency services vehicles. At 120dB, you get your entire days’ worth of noise energy in less than 15 minutes. …Motorcycle police officers are known to wear earplugs … for the noisy sirens and bikes[3].”

Types of sirens? Many. Wail, yelp, warble, air horn, piercer and whoop. I can’t quite tell them apart. No matter the type of vehicle a siren is mounted on, the only way to control the volume is through the speaker system. Some sirens sound louder than others because of the way they are mounted. “Police sirens can sound louder than ambulances or fire trucks. Police cars usually have their siren mounted low on the front bumper. Fire trucks also mount their sirens on the bumper, but the large size of the vehicle absorbs some of the sounds. Since ambulances are bigger than most law enforcement vehicles and smaller than fire trucks, their siren sounds distinctly different as well[4].”

Interestingly, I learnt that there is a lot more to sirens than just how loud they sound to me.