Animals rely enormously on sound to successfully navigate their day-to-day life. Although they communicate in many ways, vocal communication is arguably the most important. Noises can scare predators, call other members of the pack, issue a warning, indicate mating, or show dominance.
Even animals that are relative loners must communicate at least a little, if only to find a mate. While other means of communication include pheromones, touch and sight, auditory signals are widely used by the majority of species.
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Species that use sound
Birds are one of the main species that relies on auditory communication. They convey warnings of danger, defend their territory, attract mates and co-ordinate the behaviour of their group through sound. The melodic birdsong of some species isn’t vocalised just for fun – it conveys meaning.
Other species, apart from birds, communicate using sound. Monkeys generally live together in a troop and if one member spots a predator, he or she will cry out a particular call, giving other members a better chance of escaping. Studies show the Vervet monkey, a native of Africa, makes different sounds to indicate different species of predator!
Gibbons use a particular call to mark their territory. This keeps potential rivals away. A paired male and female gibbon may make the call together, while their older offspring will join in too, to deter rivals.
Frogs use sounds to attract mates – in some species, they are so loud that they can be heard a mile away! Bullfrogs are always particularly vocal during the mating season.
Water can carry sound waves in the same way that air can, as marine creatures also use sound to communicate. Dolphins make various sounds including chirps, whistles and clicks. Scientist believe that by arranging them in complex patterns, this represents a form of language.
Loudest animal noise
While some animals prefer to live quietly, so they remain virtually undetectable to predators, others make as much noise as possible. Perhaps surprisingly, research has found the loudest creature in the world is a SHRIMP! Native to the Mediterranean, the tiger pistol shrimp makes sounds greater than 200 dB – louder than gunshot fire! Water moves with such velocity that the resulting shock wave produces a loud noise, which kills other shrimps and fish up to a distance of two metres away. It is fortunate that they live under the sea, as any sounds louder than 130 dB can actually hurt the human ear, possibly resulting in deafness
The pistol shrimp has a large claw, which shoots a jet of water so powerful that it has the same effect as a mighty punch – wow, steer clear of those little suckers!
Other noisy creatures
The blue whale is the second-loudest creature on the planet. Its whistling call makes a sound of up to 188 dB, which is louder than a grenade exploding, or a jet engine. The sound can carry up to 800km under the water.
It’s no surprise the blue whale makes such a loud noise, since it is the largest living creature on earth. It can grow to up to 33 metres long and weighs up to 200 tons. Its tongue alone can be as heavy as an elephant!
Bats are particularly interesting, in that they use sound to navigate. The loudest species is the greater bulldog bat, making an exceptionally noisy sound of more than 140 dB – louder than a chainsaw! It makes the sound to track the movement of fish in shallow water pools.
People can’t hear their cries, since they are usually ultrasonic and range from 20 kHz to 200 kHz – which is outside the human hearing range.
The green grocer cicada is the earth’s fourth-loudest creature. Only the male insect makes the singing noise, in order to attract a female. The noise it makes is greater than 120 dB and can be heard up to 2.4km away.
There are many different species of cicadas and the amazing thing is that they make the sounds from a musical “drum” in their abdomen. Each species makes a slightly different sound, so it doesn’t inadvertently attract a mate from the wrong species of cicada! The sound is made by contracting their internal muscles, causing them to pulse inwards and make a sound.
Cicadas will also group together to make noises to ward off predatory birds. They have a distress call, an erratic and broken noise. Cicadas make the most effective use of sound in the insect kingdom.
Somewhat surprisingly, the king of the jungle makes only the fifth-loudest sound in the animal kingdom and is quieter than an insect and a shrimp! The roar of a lion can be as loud as 114 dB and will be heard more than 8km away. They roar for many different reasons, including establishing their territory, or communicating socially with the pride.
The use of sound to communicate is so important in the animal kingdom, that noise pollution can have a disastrous effect on our wildlife.
Excess noise impacts on birds by causing them to alter their behaviour. It can interrupt mating and prevent them from hearing other birdsong important to their day-to-day life. A study carried out by the University of Alberta, in Canada, showed significant differences in the behaviour of birds living in noisy areas.
Oven birds (a small species living in Canadian forests) fared better when living in quiet areas than they did when living near compressor stations. Pipelines keeping natural gas and oil flowing from the stations produce a constant noise and this was affecting the birds’ ability to find a mate, as the females could not hear the males’ birdsong.
Research found that birds living in quiet areas of the forest had a pairing rate of 92%, while those living near the pipes had a pairing rate of only 77%.
Studies have also revealed if a honeybee hears a sound of between 107 and 120 dB, it appears to go into shock and stops moving altogether. After about 20 minutes, it seems to recover and start moving again. This not only stops it from gathering nectar and pollen, it can also leave it vulnerable to predators.
Researchers say noise pollution is confusing and endangering aquatic life. Natural sounds pose no threat, so the noises produced by the motion of the water, or the marine creatures themselves, aren’t harmful, but the unnatural noise produced by people is taking its toll. This includes the “ping” of military sonar systems, the blasts of offshore development, the roar of motors, seismic noises from gas and oil exploration, coastal leisure activities such as motorboats, and commercial shipping traffic.
Sonar systems alone can create sound waves of around 235 dB – louder than a rock band which generates sound of up to 130 dB. Marine creatures living in their wake are unable to communicate with each other, as they can’t hear normal sounds. This seriously impairs fishes’ ability to understand what’s happening around them and can lead to a shoal being attacked by a predator, resulting in mass deaths.
Ship-owners are taking action to combat the problems by using rubber to reduce the noise of their machinery as they travel through the ocean. The practice has been used on mega-yachts and warships for some time, but now it’s becoming more common on commercial ships as well.
Sound Planning provides a range of noise control services and products aimed at controlling excess noise. Please contact us to find out more about our bespoke solutions.