In animals, sound production is the means of information transmission amongst the species. There are two sources of sound production. They are vocal sources and mechanical sources. The sound produced from these sources hence is classified as vocal and mechanical. The vocal audio production happens through the respiratory system and the mechanical audio production happens through the contact of the body parts or by contact in-between two or more elements of the environment. The vocal audio production is a unique quality of the vertebrate animals while the non-vocal sounds are produced by many of the invertebrates along with the animals belonging to all the vertebrate classes as well.
Mechanical Sound Production
The two types of sound - the vocal and mechanical sounds are produced from different sources. Vocal cords, as already known, are a common feature among vertebrates whereas invertebrates are the ones that utilize different body organs for sound production. In fact, many of the animals possess a variety of special structures that produce mechanical sounds. For example, crickets and grasshoppers produce sound by rubbing together their structures that are present on their wings. Cicadas, which are known to produce the loudest sounds amongst the insects, emit their sound through the pair of membranous organs which are present at the bottom of their abdomen. A unique feature of this insect is that there is a special muscle that deadens the hearing organ when it produces sound for calling.
The mechanical means of production of sound exist not only in invertebrates but vertebrates as well. There are various organs in the vertebrates as well that produce mechanical sounds. For example, many avians (birds) belonging to diverse species and groups produce sound through their wings during their flight. Another one of the most common examples of mechanical sound production is the rattling sound produced by rattlesnakes. This is done with the help of the modification present on the tip of its tail. Various members of the vertebrate class also produce mechanical sounds with organs that are evolved and specialized for different functions. Examples of these include the stomping and drumming of the ground by members of several species with the help of their feet. This when transferred to the water terrain creates a slapping sound as well. The slapping can be done with the help of a tail as well which also serves as a warning signal by the aquatic animals.
Aquatic animals also produce sounds such as the sounds produced by the moving bones and the teeth of the fish against each other. Sometimes the swim bladder acts as a resonating cavity. In reptiles, crocodiles and turtles produce low-pitched sounds. Likewise, the lizards and snakes produce hissing sounds under stress.
Vocal Sound Production
Vocal sound production requires specialized structures like the lungs, mouth and trachea. An example of such usage that results in sound production is the sound produced by frogs. The frogs are highly vocal and produce species-specific sounds with the movement of the air between the mouth and the lungs past the vocal cords in the windpipe or trachea. The vocal sounds of the birds are usually produced by the syrinx which is a specialised region present at the lower end of the trachea. This is different from the mammalian vocalisations which originate in the larynx which is a modification of the upper end of the trachea.
In humans, there is a vocal tract that acts as the source of sound production. This vocal tract is a cavity not only in human beings but also in animals that act as a filter. The birds as already mentioned consist of the trachea, the syrinx, the oral cavity, the upper part of the oesophagus and the beak. Similarly, the mammals consist of the laryngeal cavity, the pharynx, the oral cavity and the nasal cavity.
Modern Sound Production For Music
Traditionally, music has been a mechanical sound production that was done by the combination and striking together of various elements found in nature. Common instruments of music have included piano, violin, etc and Indian musical instruments like the veena, sitar, etc. With the increase in technology and the day to day utility, there have advancements in the field of music as well. There are certain computer programs and audio programs that not only are useful for playing old and classical music but also for new audio production. The modern technological advancements also include a sound mixture machine that allows tunability and mixing of various musical instruments for making melody. Most contemporary music, especially Bollywood music, has a definite pattern of an audio program that not only involves edits while recording the music and songs but also changes in the audio post production. These are done with the help of computer software and various other advancements that have occurred over the years in the music industry.