When Swiss biotech firm Auris Medical wanted to recruit patients to test its experimental hearing loss drug, it decided to enlist partygoers deafened by firecrackers on New Year's Eve, Reuters reported.

In the weeks leading up to December 31, 2005 it advertised in the subway and on radio stations in Munich and Berlin, urging victims of sudden firecracker-induced hearing loss to turn up at designated clinics for treatment on January 1.

"We had just one single day of enrolment, we didn't know how many people would show up," Thomas Meyer, managing director of Auris, said.

Luckily, his gamble paid off and the small private company is now one of the leaders in what has been an empty space for the pharmaceutical industry.

Auris managed to recruit enough people to show that its compound AM-111 posed no safety risk and has since successfully completed a mid-stage trial in acute sensorineural hearing loss, or sudden deafness, involving 210 patients.

While there is no guarantee that its drug, which is injected through the eardrum, will pass muster in final-stage tests, the progress by Auris and a clutch of rival biotech firms is making large pharmaceutical companies sit up and take notice.

There are currently no approved disease-modifying drugs for hearing loss, which affects nearly a third of people aged 65 to 74 and half of those over 75.