U.S. scientists say they have, for the first time, changed high frequency sounds into light by reversing a process that converts electrical signals to sound.

The Lawrence Livermore National Laboratory researchers said their new tool enhances the way computer chips, LEDs and transistors are build.

Commonly used piezo-electric speakers, such as those found in a cell phone, operate at low frequencies that human ears can hear, the scientists from LLNL and the Nitronex Corp. said. But by reversing that process, lead researchers Michael Armstrong, Evan Reed and Mike Howard used a very high frequency sound wave -- about 100 million times higher frequency than what humans can hear -- to generate light.

"This process allows us to very accurately 'see' the highest frequency sound waves by translating them into light," Armstrong said.

The complex research appears in the journal Nature Physics.