Infrasonic Vibrations Made By Elephants

Elephants make sounds that humans cannot hear. Human ears hear sounds above 20Hz, Deep throated sounds made by elephants can be as low as 12Hz. If we stand close to an Elephant, we can feel vibrations from these low frequency sounds. Such infrasonic (low-frequency) sounds made by elephants are called Rumbles.

Scientists in the field of bioacoustics (bio-acu-stiks), study sounds made by living beings. They say elephant rumbles resemble tremors made by small earth quakes. Have you heard of dogs sensing an earthquake before humans. They feel vibrations made by earthquake's infrasonic sounds from deep under. While dogs feel these infrasonic sounds, Elephants can actually make them.

How are sounds made ?

There are two bands of muscles called vocal chords, inside the voice box or larynx in our throat. They vibrate when we speak, making sounds. Elephants are huge, so are their vocal chords. Average human vocal chords measure 17mm in length. Elephant vocal chords are longer than 10cm, making them 6 times bigger. These long and loose vocal chords help elephants make low frequency sounds.

Picking up infrasonics

Unlike sound waves that travel by air, elephant rumbles travel several kilometres through the ground. Elephants use nerve cells in their feet to detect infrasonics and send signals to their brain, where it is decoded and understood. When it comes to ears, Elephants have big ears with a long ear canal. Their ear drums, which is a part of the ear that picks up sound, is big and strong. It can detect low frequency sounds clearly.

Understanding the language

Scientists are working on recording elephant rumbles. Computer programs analyse them and identify patterns. Current estimates show more than 140 types of rumbles, each one with a specific meaning. It resembles words in a language. Every elephant rumbles at a unique frequency, like having its own voice. Pitch and loudness change in rumbles, much like humans having a conversation. Recent research indicate elephants give each other infrasonic names, and use it to call each other.

Elephant rumbles help to track, monitor and protect Elephants. Rangers detect frantic calls, locate poachers, and rescue injured animals by monitoring Elephant rumbles. Tapping in to elephant talk has a big impact on elephant conservation efforts.