The company Philips, for whom Ottens developed the compact cassette in 1963, confirmed his death to DPA on Thursday. He died in his home town of Duizel in the Netherlands.

Ottens' invention overhauled the music market, and he later also contributed to the invention of the compact disc.

"Lou was a special man," Olga Coolen, head of the Philips museum in Eindhoven, said. "He loved technology, also the humble beginnings of his inventions."

He started showing an interest for audio devices as a child.

During the German occupation in World War II, he crafted a radio to be able to listen to the underground free station Radio Oranje with his parents. The device was equipped with a special antenna to avoid German jamming transmitters.

After the war, he became an engineer at the electronics firm Philips, which made him head of product development in 1960.

In 1963 he presented the first cassette at an electronics fair.

He had cut out a piece of wood that could fit into his breast pocket and established his new invention should be no larger than that.

"The compact cassette was actually invented out of spite against the tape recorder, easy as that," Ottens later said.

The success of his invention surprised him, Coolen said. "More than 100 billion were sold worldwide," she said.

Australian Associated Press