A Swedish man broadcast music from his stomach for several hours via a mini audio system. But he was disappointed by the sound quality.

The sound was "bad, bad. It was a very bad sound. But that was not the important thing, I just wanted to show that it worked," said Fredrik Hjelmqvist, 45, owner of the hi-fi equipment shop Pause in Stockholm.

"It was a success, we were the first in the world to do this," said Hjelmqvist, who hopes to sell his invention for around 12,800 euros (17,000 dollars). 

The plastic capsule -- called the "Gutpod" -- containing the device is about three centimetres long (1.2 inches) and 1.5 centimetres (0.6 inches) in diameter and contains a miniature battery-powered audio device.

The music was heard by using a stethoscope connected to an amplifier.

After about three hours, however, the muted strains of Gloria Gaynor's "I Will Survive" and the Village People's "YMCA" faded and could no longer be heard.

"The operation shouldn't in any case last beyond this weekend, for natural reasons," Hjelmqvist added.