It's an old wives tale that singing to plants helps them grow; but could the same be true for solar cells?

New research suggests playing pop and rock music improves the performance of nearby solar cells, an Imperial College London news release reported.

The pitch and frequencies of the music are believed to cause vibrations that enhance the ability to generate energy of solar cells that contain clusters of 'nanorods'. The practice can improve the cell's performance by a whopping 40 percent.

These findings could help researchers improve solar energy production, and even make it more economical.

The team took zinc oxide nanorods attached to a polymer that allows sunlight to be converted into energy, and tested their theory.

The researchers found sounds of about 75 decibels (the level of roadside noise) or higher gave the solar cell a significant boost.

"After investigating systems for converting vibrations into electricity this is a really exciting development that shows a similar set of physical properties can also enhance the performance of a photovoltaic," Doctor Steve Dunn, Reader in Nanoscale Materials from Queen Mary's School of Engineering and Materials Science, said.

Researchers had noticed in the past that applying certain strains to a zinc oxide materials could improve output; a process known as the piezoelectric effect.

"We thought the soundwaves, which produce random fluctuations, would cancel each other out and so didn't expect to see any significant overall effect on the power output," James Durrant, Professor of Photochemistry at Imperial College London, who co-led the study, said.

This turned out not to be the case.

"The key for us was that not only that the random fluctuations from the sound didn't cancel each other out, but also that some frequencies of sound seemed really to amplify the solar cell output - so that the increase in power was a remarkably big effect considering how little sound energy we put in," Durrant said.

"We tried playing music instead of dull flat sounds, as this helped us explore the effect of different pitches. The biggest difference we found was when we played pop music rather than classical, which we now realise is because our acoustic solar cells respond best to the higher pitched sounds present in pop music," he said.