In physics, the sound is produced as a pressure wave. When an object vibrates, it creates a pressure wave, which produces sound. This pressure wave causes vibrational motion in the particles in the surrounding medium (air, water, or solid). When particles vibrate, they move nearby particles, causing the sound to travel further through the medium. Sound comes from a specific source and can be distributed or scattered in a variety of ways. Only a medium, such as air, glass, or metal, can allow sound waves to travel. Transverse waves, pressure waves, and mechanical waves are the three types of sound waves.

In animals, sound production is the initial stage of sound as a way of information transmission. Mostly, vocal sound is only produced in vertebrae animals and several invertebrates and also some members of vertebrate classes make non vocal sounds. The meaning of producing vocal sound by vertebrates is using their specialized body part such as stamping or drumming on the ground with the feet is seen in many species and slapping the water with the tail is a common way for aquatic mammals to warn others of danger.

Elephants can communicate over long distances. This is because elephant uses infrasound. Infrasound frequencies are good for long distance communication because they travel well through objects instead of being reflected. It is estimated that elephants can hear each other as far as 4 km away, which means elephants can hear each other within a 50 km square area. According to a report published in Animals, elephants can hear approaching thunderstorms from more than 100 kilometres away and can theoretically make their way towards them. This would be a useful skill to have near the end of the dry season in much of Sub-Saharan Africa, where water is a scarce resource. According to PBS, there is also anecdotal evidence that elephants in Thailand may have been able to detect an impending tsunami.

The bat emits sound waves from its mouth, and when those waves collide with an object, an echo is created. This echo is returned to the bat's ears. The bat can interpret the echoes to determine the object's size, location, and shape. The bat can quickly alter its course to intercept its prey by constantly emitting these sound waves. Bats' echolocation sounds are ultrasonic, which means they are very high pitched that humans cannot hear them. Humans can only hear sounds between 20 Hertz and 15-20 kHz, whereas bat echolocation sounds range from 9 kilohertz (kHz) to 200 kHz. The different frequencies of the sound waves emitted by the bat, provide information such as the speed, direction, size, and position of the object hit by the waves. Bats have specialised ears, muscles, and cells for interpreting information from echoes. When a bat listens, its external ear structure aids in receiving echoes, and specialised ear muscles prevent internal damage. These frequency changes create an image in the brain, allowing the bat to make rapid adjustments to its speed and course to catch prey or avoid an object.

In addition, whales also use echolocation. When air is blown through the blow hole, internal lips near the edge of the blow hole vibrate, causing these sounds to be produced. These vibrations are then focused on the head by large fluid-filled structures. This structure is known as the spermaceti organ in whales. When sound waves travel into the water, they will bounce back when they encounter a solid object. Because whales lack ears, returning sounds are picked up or "heard" in the whale's jawbone. Most whales' jaw bones are hollow, fluid-filled, and have nerve endings for sound detection. These whales can see by sound thanks to echolocation. It is possible that whales perceive their environment through sound rather than sight.

Imran, Ikram, Khairina, Balqis, Aina Suhaiza 

Date of Input: 22/03/2022 | Updated: 01/02/2025 | emma