Fans of loud rock music could owe their love of noise to fish, scientists say.

Researchers at Manchester University say rockers may be responding to a pleasure-inducing hearing mechanism passed down through millions of years of evolution from fish to humans.

They found part of the balance-regulating vestibular system in the inner ear, known as the sacculus, responds to sound frequencies that predominate in music.

The sacculus is not thought to have any hearing function in humans and only appears to be sensitive to loud volumes, above 90 decibels.

Team leader Neil Todd, an expert in music perception, told New Scientist magazine: "This primitive hearing mechanism from our vertebrate ancestors appears to have been conserved as a vestigial sense in humans."

He said the sacculus has a connection to the part of the brain responsible for drives such as hunger, sex and hedonistic responses.

"A classic example is the haddock mating call which encourages the fish to produce sperm and eggs," he said.

Mr Todd believes this could be why people get a pleasurable buzz from music, and why it has developed into such a powerful cultural force.

In tests, 11 students listened to tone pips of varying frequencies.

Their saccular sensitivity was found to range from 50 hertz to 1,000 hertz, peaking between 300 and 350 hertz.

Rock concerts

On a musical scale, middle C has a frequency of 261 hertz, and male and female voices have frequency ranges of up to 200 and 400 hertz respectively.

"The distribution of frequencies that are typical in rock concerts and at dance clubs almost seem designed to stimulate the sacculus," Mr Todd said.

"They are absolutely smack bang in this range of sensitivity."

Large groups of people singing or chanting, such as a choir or a crowd of football fans, could also stimulate the sacculus, he added.