Quirks & Quarks

Animals vocalize 100 times louder than humans - it's a matter of survival

With a combination of high pitch, a wide open mouth and clever use of body shape, animals are extraordinarily efficient noise makers
Birds like this robin communicate so efficiently because of their high pitch, a wide-open beak and the retraction of the head into the body to create a reflective surface to direct sound forward (Charlesjsharp)

How animals holler

Animals make sounds by moving air from the lungs, through the throat and out of the mouth into open space. According to a new study led by Dr. Ingo Titze, the executive director of the National Center for Voice and Speech at the University of Utah, they do this with what is called a radiation efficiency. This refers to the fact that with a combination of high pitch, a wide open mouth, and the ability to direct sound with use of specific body shape, some animals can communicate loudly and clearly over long distances using nearly 100 percent of their vocal power. 

The screaming piha is one of the louder birds in the Amazon rainforest

Why small birds chirp above their weight

Tiny birds are a great example of animals that have an uncanny ability to make sounds at a volume you'd think would be beyond their weight class. In Dr. Titze's the experiment, they looked at the Screaming Piha, a bird from the Amazon rainforest. At a distance of one metre, it easily chirped at 110 decibels. In contrast a trained opera singer struggled to hit the same mark from the same distance despite being vastly larger than the bird.

Like many birds, and some mammals, the piha is able to accomplish this by using its entire body as a sound baffle. It cocks its head and retracts it back into its body. In this way, the body becomes a reflecting surface that directs the sound forward. 

In another experiment, the group studied the sound of the Rocky Mountain elk. It makes a surprisingly high pitched trumpet call. The elk is able to do this because of a thick ligament in its vocal tract. The animal is able to put an enormous amount of tension on the ligament by stretching the neck, resulting in the high pitch of its call. 


The Rocky Mountain elk makes a surprisingly high pitched sound for such a large animal 

Animals are better at sounds than humans (if better is louder)

Humans are only able to broadcast about 1 percent of their vocal power through speech. This is because human speech involves more complex sounds - including vowels and consonants - that require a lot of variation of the use of lips, tongue and jaw. This complexity requires a low pitch, which does not carry as far as the high pitch of animal sounds. Also, humans are not able to reshape the head or neck to help direct sound.

The researchers believe humans may have lost the ability to make more efficient long distance calls - particularly emergency calls like those animals make - and that technology may have played a role.