What Causes the Sound We Hear During Bus Travels at Night?

If you have noticed, we never hear the humming sound that puts us to sleep in buses in our private vehicles. So why do we only hear this sound on buses? Or we can say, why do we hear this sound?

Especially during long night journeys, when we lean our heads against the bus window, feeling slightly tired. we hear a humming and this sound strangely gives us peace. We fall asleep while the sound is ringing in our ears.

There are even 1-hour videos on YouTube with only this sound. your voice what sound is it We don’t know if you’ve ever questioned it before, but if it aroused curiosity in your mind when you read the title, let’s take you towards the details of the content.

Let us remind you for those who do not understand the sound:

The operating principles and parts of private cars and large vehicles such as buses and trucks are generally different from each other.

automobile brake system

If we give an example of the difference between small cars and buses; trucks are generally used to control heavy loads. special braking systems While small cars use standard braking systems.

Here’s what we don’t hear in our private vehicles. The reason for the sound we only hear on bus trips is In fact, it stems from exactly such a difference.

When we understand the difference between the brake systems in buses and small vehicles, we will also learn the source of the hum.


As we just mentioned, cars have lower weight than buses. disc or drum A relatively easier braking system is used. Vehicles such as trucks or buses also have different braking systems as “primary” and “secondary”.

The system we call “primary” is actually a combination of pads and brake discs, just like in our cars. by the principle of friction it works. The system we call “secondary” includes exhaust brake, engine brake and hydraulic retarder, etc. covering systems. These secondary braking systems are called retarders.

So what is this retarder and what does it do?

bus brake

The sound we hear on buses, which creates an “ASMR” effect and puts us to sleep, means that the retarder is working. Retarder that provides deceleration, It kind of supports the braking ability. In fact, the origin of the word means “slowing down”.

We can also explain it this way; It reduces wear and extra costs by ensuring less use of brake pads, from steep slopes They offer safety by preventing the risk of brake release when descending, and since the intensity can be adjusted by the driver, they can also adjust the torque control at different levels.

Now that you know the source of the sound, you can fall into a more peaceful sleep by listening to the humming sound…

If you would like to take a look at our other content that may interest you:


Can You Know What These Buttons and Symbols in Cars Do?


“I’m a Car Enthusiast!” How many times will you be able to do this test that will be difficult for even those who say it?


For those who say “I can recognize a car even from its interior design”: Can you guess the model and year of these cars correctly?


Why is the ignition key on the right in almost all cars, but on the left in Porsches?


Bad News for Window Seat Lovers! What is the Safest Seat on a Passenger Bus During an Accident?


Why Are Bus Steering Wheels More Curved and Larger Compared to Car Steering Wheels?


Why Are the Front and Rear Rims of Trucks or Buses Different?

source site-40