The dolphin adapts sonar to distance

2003/10/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Zoologia

Researchers at the University of Hawaii find out why the echo does not extol when the dolphin uses sonar: as it approaches an object it emits smaller volume clicks so as not to damage the ears when it rises back.

The dolphin emits a sound and receives the echo. Thus, as he approaches an obstacle or prey, he emits the sound more and more.

It seems that the dolphin cannot adapt the ears to the volume of sound, such as bats, so as it approaches the obstacle it uses a lower volume, and when the wave returns it does not damage the ears of the issuing dolphin.

To this conclusion they have arrived while recording the sounds of the sonar of the stomach. For this purpose hydrophones or aquatic microphones have been used. And as the dolphin approaches the hydrophone, they have measured that the volume for each half way descends six decibels.