Dolphin Communication & Echolocation
One of the amazing things that dolphins use for communication and to find out about their environment is echolocation. It is something that has been studied but still many questions remain. Most experts agree that this has been the result of evolution over a long period of time. The use of echolocation involves the dolphins sending sound waves through a click. Once those sounds hit something then vibrations come back to the dolphin.
That information that is returned allows them to find out what is around them. They can find out where objects are located and the distance. They can also find out the size and the shape of that object. The longer it takes for the sound waves to come back to them, the further the object is from them. The idea of echolocation was first investigated by Jacque-Yves Cousteau and he wrote a book on the subject in 1953.
The power from dolphin echolocation is amazing, and there are humans that have reported feeling the buzz from it when in the water with them. Humans can’t hear it but they can feel it taking place around them. This continues to be one of those mysterious elements of echolocation that needs to be further investigated.
The frequency of echolocation can be 120 kHz. Humans have the ability to hear about 20 kHz. Dogs and cats are said to have good hearing, but even what they offer doesn’t compare. For example, dogs are at 45 kHz and for cats it is about 65 kHz.
There is a melon in the head of dolphins that is a big part of the echolocation process and transmission. The melon contains fat and the lower jaw is the actual transmitter. The teeth are similar to antennas and allow the signals to be sent. The process is very complex and a great deal of research involving the anatomy of dolphins has been done to find out answers to such information.
Dolphins are well known for their clicks and whistling sounds, and both are believed to be a big part of the echolocation functionality. The dolphin passes air through the blowhole using the air sacs. This is similar to the idea of filling up a balloon with your air and pinching it closed with your fingers. Then you slowly release some of the air out of the balloon. There is a bi-sonar signal generator behind the blowhole and the vibrations allow the echolocation to be implemented. This is often called the echolocation pulse.
The lower jaw is vital to the process of echolocation to occur. It is believed to work for dolphins the way that the outer ear works for a human. This provides dolphins with information so that they can identify the direction that sound comes from. Keep in mind that in the water, sound travels 4 ½ times faster than it does on land.
You may find it interesting that high frequency sounds aren’t able to travel a long distance in the water. There is a plenty more energy associated with the low frequency sounds so they go further in distance. Dolphins typically use echolocation to identify items that range from 16 feet to 656 feet from where they are located. This has caused many experts to wonder why dolphins collide with boats in the water if they can hear so well. The results of such research indicate that noise pollution including boats can cause problems for echolocation to work properly for dolphins. Other risks include offshore drilling, commercial fishing, and sonar testing.
It is possible such noise pollution can deplete the hearing of dolphins over time. It can also result in them being disoriented so that they have a harder time navigating through the waters. Such noise pollution can be so extensive that some dolphins die from a hemorrhage that occurs inside of the ears. This is information that really drives home the fact that conservation is a key part of helping the dolphins to survive in the wild.
The term bi-sonar is also referencing echolocation, and you may have heard it used in regards to other forms of living creatures. Dolphins aren’t the only ones that use it but they are believed to have system that is significantly developed and advanced compared to the others. Only additional research over time will give us all the answers about echolocation and what all it entails.
Understanding the basics of it though has given us breakthrough information for dolphins. Realizing how humans and machinery can prevent it from working like it should also indicates that there can be risks when the world of animals and humans are too closely linked. The fact that humans continue to be found in all the bodies of water as dolphins, it makes it hard to draw that line.