Inspired by the extraordinarily acute hearing of marine mammal orcas, Stanford researchers have developed a highly sensitive underwater microphone.
The new hydrophone can capture the whole range of ocean sounds, from the equivalent of a soft whisper in a library to an explosion of a ton of TNT just 60 feet away, at any depth and even under crushing pressure.
It also can hear sound frequencies across a span of 17 octaves, spanning pitches far higher than the whine of a mosquito and far lower than a rumbling foghorn.
"Orcas had millions of years to optimize their sonar and it shows. They can sense sounds over a tremendous range of frequencies and that was what we wanted to do," said Onur Kilic, a postdoctoral researcher in electrical engineering and lead author of the study.
"It is a very high dynamic range microphone, able to sense everything from the weakest sounds to those 100 million times stronger," he said.
The research was published in the Journal of the Acoustic Society of America earlier this year.