Mumbai, May 29: Advertisers are waiting to hear from media research firms the most accurate figures on FM listeners.

At one such event in the city recently to arrive at the most conclusive findings, a new tool, called the radio audience measurement plan, was unveiled. The plan, brought to the table by TAM Media Research, revolves around the internationally popular diary method.

As the plan rolls in India, bands of 480 listeners in Mumbai, Delhi and Bangalore will be surveyed. Listening habits over a week will be monitored. “Calcutta will have to wait. But we hope to get the findings on the FM stations there by next year,” said Siddhartha Mukherjee of TAM Media Research.

At present, findings of the Media Users’ Research Council are used to gauge the number of listeners in Mumbai, Delhi and Calcutta.

“The council uses the day-after recall method. But the world over, the diary method is more acceptable,” says the chief of a top media planning firm.

“Radio City, Big FM, Red FM, Fever FM and Hit FM have chosen TAM’s method,” said Mukherjee. More could join the fold.

In 2006, advertising revenues for FM operators increased 58 per cent over the previous year. That translates into a gain of around Rs 500 crore. With so much money at stake, whatever the method of counting listeners, it better be accurate.