Vancouver (British Columbia) - A Canadian bank is collecting tens of thousands of unwanted tennis balls, which it says it will recycle to reduce noise levels in primary schools.

The donated balls will be sliced open and stuck on the bottom of the legs of school chairs and tables to muffle classroom noise and make it easier for students to learn, Montreal-based National Bank of Canada says.

'A lot of schools have told us it works,' said spokesman Valerie Lamarre.

Last year, the first time it held the drive, National Bank collected more than 53,000 used tennis balls and gave them to 150 primary schools in the province of Quebec, Ms Lamarre said.

The idea is linked to the bank's sponsorship of the Rogers Cup tennis tournament, being held this week in Montreal and Toronto.

Used tennis balls can be dropped into recycling bins at National Bank branches until Aug 8. -- REUTERS