How Many Decibels Is a Car Horn?

Contrary to what many people may believe, the horn on their vehicle is not put there to honk at people that don’t go as soon as the light turns green or at a pedestrian taking a little extra time in the crosswalk. In many places, it is actually illegal to honk a car horn aggressively or for any reason other than what they were designed for, which is to alert other road users of potential accidents, hazards, or your presence.

Why Are Car Horns So Important?

Car horns are so important due to their purpose of alerting other users of potential accidents or hazards. This is of course why it is integral that drivers only use their horns for these purposes rather than to make their anger or aggression known. The sound of a car horn should alert other drivers that there may be an unforeseen hazard ahead, or they are switching lanes without seeing a car in their blind spot, or that they are pulling onto a busy road without seeing another coming. 

Most people that have been driving for any significant time at all can likely recall times when they’ve used their horns for any of the aforementioned reasons and they were thankful for the horn being there. If someone is pulling out of a parking lot and they don’t see you coming down the road at 45 mph, sounding your car horn could literally be the difference between life and death if it alerts the other driver to stop and everyone makes it through without an accident.

Cars are big and heavy pieces of machinery, and moving at the speeds that they do on a normal basis, it can be frightening to imagine the damage that they can do if something goes wrong. In just a couple of seconds, various lives can be altered by a car accident, and many accidents are avoided every day just by people correctly using the horns in their cars. 

How Many Decibels is a Normal Car Horn?

Decibels are a unit of measurement that measures the intensity of sound, although it may not be a common term known by many people. The actual unit of measurement may not mean a whole lot just by hearing the world, so let’s take a look at a couple of examples to start making sense of the unit.

Starting with something that most people will perceive as being quiet, a whisper is typically around 30 decibels, so that may give you an idea of just how quiet one decibel would be. About twice the sound level of a whisper is normal conversation, at around 60 decibels. Above that, you may find that a lawnmower operates at around 90 decibels. Finishing off this example is a firecracker, which typically releases noise at around 125 - 150+ decibels.

With that in mind, how many decibels is a normal car horn? With the above taken into account, you may be thinking that a car horn would likely fall in between a lawnmower and a firecracker, and you’d be exactly right. A typical car horn operates at between 100-110 decibels, which makes it loud enough to be able to hear through multiple vehicles and over the typical noises of the road. The loudness of a car horn is essential because they need to be able to be heard by someone who is typically not paying as much attention as they should be. The reason the horn is being sounded is usually that the person needs to be alerted, so it is essential they are loud enough. 

Are There Car Horn Regulations?

Due to the extreme importance of car horns for the general safety of society, there are of course regulations that must be adhered to when it comes to their sound, noise level, placement, and use. Failure to follow these regulations will typically lead to receiving a written violation if not worse. Some of the most common regulations on car horns are as follows: 

Aggressive use — As discussed previously, car horns are only to be used to alert others to danger or a hazard in the roadway. Using a car horn aggressively or out of anger can be cause for a ticket in many jurisdictions.

Time — Although this will certainly differ from place to place, the ability to use a car horn is prohibited — except when necessary to prevent an accident — during certain hours, usually at night. The exact timing of the limitations will be different in various places, but a general rule of thumb is that they shouldn’t be used between the hours of 11:00 pm - 7:00 am, again unless it is being used correctly.

Type of horn — Some people out there like to modify the horns on their vehicles to play different tones or make different sounds other than the typical horn sound that is used on vehicles. A couple of the more popular choices include the sounds of a clown car or a train horn, but some people even go as far as to use a police siren as their horn. This can lead to a myriad of different issues as the noises can begin to be more distracting to other drivers than an actual warning. 

Noise levels — following up with the previous discussion of how loud typical horns are, different places will have varying restrictions on the noise level that horns are allowed to be. This is often limited to the range of 150 - 175 decibels, which is where it starts to ban train horns and the like.

The bottom line when it comes to the horns on your vehicle is to simply use them for the purpose that they were intended, and don’t make too many modifications to the system. They are meant to help people and to keep everyone on the road safe and should be used for that reason