One point or another, people become curious to know whether the fish can hear sound or not. My curiosity in this subject began when I was a child.
One of my older friends, with whom I usually went fishing, used to tell me that we need to be so quiet if we want to fill our buckets with fish.
He went on to explain that when we make loud noises or even raise our tone, we can scare off fish.
After years of holding this question back in my mind, I decided to find its answer by going through scientific works.
So, can fish hear a sound?
Here is the short answer:
Fish can hear sounds. They have two hearing systems: the auditory system (the inner ear) which they use to capture sounds, and the lateral line system to detect vibrations. These two systems are independent organs but their functions are interconnected.
Hearing is very important for fish to know their environment. A post published by the University of Rhode Island offers a great example of how fish utilize their auditory system in the dark marine environment. Think of a dark room. There, the best sense to have is hearing as the vision can’t penetrate the darkness in the deep sea.
Fish Ears
Fish have inner ears, which are also known as otoliths. The fish ears or otoliths are made of calcium carbonate which is denser than the rest of the fish’s body and water.
Not all fishes have the same hearing ability. Some hear better than others or vice versa.
It all depends on fish cilia (nerve hairs), otoliths, bladders, mechanoreceptors, and accelerometers.
The fishes with better hearing ability are blessed to have all those parts. Unfortunately, some have only one of those, which limits their ability to hear well.
The Lateral Line System
Thanks to the lateral line system, a fish can sense the sound through vibration and they can estimate the proximity of the moving bodies. This function is very handy for some fish to protect themselves from approaching threats.
The Lateral Line System is also known as Lateralis System. This system consists of a network of mechanoreceptors (neuromasts) that locates all over the fish’s body and head.
The organ’s primary function is to detect pressure changes and movements in the surrounding water.
Mechanoreceptors can appear both on the surface and below the fish skin. However, in most fishes, those receptors are embedded in the mucus-filled lateral canals.
How important is hearing for fishes
Thanks to hearing abilities, fishes obtain a great deal of information about their environment.
Generally speaking, they utilize their hearing to find a location of sounds, to determine the direction, to communicate with each other, to detect the moving bodies and object, and to protect themselves from approaching predators.
Therefore, interfering with the detection of sound in the areas where the fish population is dense can harm the lives of fishes.
Do fish hear better than humans?
Although fish may be better at detecting sounds underwater, their general hearing range is considered to be lower than most mammals. Compared to fish, human ears are exceptionally good at hearing.
More specifically, the hearing frequency range of an average person is between 20 to 20,000 Hz. However, the human hearing range gets narrower as they age.
On the other hand, depending on the species, the hearing frequency range of fish is no more than 800-1000 Hz.
For more information, you may refer to the hearing range chart below:
Since sound travels at a much faster speed in water than they do in the air, some species of fish can detect sounds underwater from a longer distance.
Which species of fish have better hearing.
Types of fish that live in the deepest and darkest parts of the ocean have better hearing.
More specifically, fishes that live 400 to 4000 meters (0.2 to 2.5 miles) below the surface developed a better hearing system thanks to the evolution.
Scientists believe the lack of sunlight in that depth made fishes rely heavily on their hearing to survive.
Primary takeaways:
- Fish can hear sounds through two distinct but functionally related hearing systems: Inner ears (otoliths) and the lateral line system. Fishes’ inner ears locate inside their head. The lateral line system, however, runs through their body and connects to their head.
- Fish’s Inner ears serve as an auditory system, while the lateral line helps them to detect vibrations and movements.
- The hearing system is important for fish to survive. Using inner ears and the literal line system, fishes move from one place to the other, communicate with each other, detect movements, and protect themselves from approaching threats.
- Fish can hear better in lower frequencies and they are good at hearing underwater because of the evolution. However, compared to most mammals, fishes have a narrow hearing range. For example, the average human’s hearing range is about 20 to 20,000 Hz, while fishes cannot hear frequencies over 800-1000 Hz.
- Fishes that live in the darkest and deepest parts of the ocean have better hearing. Because they adapted to that deep and dark ocean environment relying heavily on their hearing abilities.
