It’s a known fact that human beings observe most things using their sense of hearing. However, there a limit to their hearing capabilities and can perceive only certain sound frequencies that lie between 20 Hz and 20,000 Hz.

Researchers at the Aalto University, Finland, have developed a new audio tech that will enable people to hear ultrasonic sources that generate sound frequencies over 20,000 Hz. The findings were in Scientific Reports early in June, which also show that the technique would also allow people to understand the direction from which the sound is coming.

Bat sounds used for the study

In the study, researchers employed bats as the source of ultrasonic sound. Leveraging the new audio technique, the team was able to hear the direction of arrival of bat sounds, allowing them to track the bats in flight accurately.

While there are devices that allow humans to hear bats, the novel tech lets them locate the source as well. Researchers achieved this by recording the sound using a microphone setup mounted on a small sphere, performing a sound-field analysis, and obtaining the most prominent direction of the origin of the sound. Besides, a parameter also determines if the sound is coming from a single source.

Many practical applications possible

The signal is pitch-shifted to audible frequencies and a sound is played in the headphones in real-time. This allows the listener to perceive the sound and its origin based on which it was analyzed. Scientists believe pitch-shifting can be achieved using electronics placed on headphones as well.

Researchers have also suggested the practical applications of the new audio technique. Minor pipe leaks and at times even damaged electrical equipment produce an ultrasonic sound that goes unnoticed. The new tech will allow people to detect the location of faulty equipment and fast-track the repair process.