Updated

The owners of a German sewage treatment plant called on scientists to investigate Wednesday after they claimed playing Mozart motivates the plant's microbes and makes them more productive.

Roland Meinusch, manager of the plant in Treuenbrietzen, about 70 kilometers (43 miles) southeast of Berlin, said by playing Mozart's Magic Flute on a half-hour loop, the plant produced 1,000 cubic meters (35,300 cubic feet) less sewage sludge than normal, saving €10,000 ($13,600) over the past year.

The harder the microbes work, the more sewage they digest which produces more clean water and less sludge, he told The Local news website.

"And the less sludge we produce, the less we have to pay to farmers for them to put it on their fields," Meinusch added.

He said the plant was contacted by a company making special loudspeakers that had apparently achieved positive results at an Austrian sewage plant.

They decided to install the speakers in March last year but almost stopped the experiment a few months later as nothing was happening.

However, they continued the experiment and found that after a year the plant was left with 6,000 cubic meters of sludge, compared with the usual 7,000 cubic meters it produces.

Meinusch said, "Of course as an engineer, I cannot say whether what we achieved was actually due to the music -- nothing has been scientifically proven. I would hope to attract someone from a university to come and study it, perhaps a student who needs a subject to investigate for a diploma or doctorate."