Jakarta – Former vice president Jusuf Kalla said half of the country's mosques were equipped with poor quality sound systems and that such subpar sound meant they caused noise pollution.

"Mosques must have high quality sound systems: This must be fixed," said Kalla, who is also chairman of the Indonesian Mosque Council (DMI).

Kalla said as a result of the bad sound quality worshippers could barely hear the sermons delivered by Muslim preachers.

"However noble the message may be, if the sound system is bad, people will doze off and miss the message," he said as quoted by tribunnews.com. Kalla said that the DMI would initiate a countrywide sound system donation program.

Currently, there are more than 250,000 mosques in Indonesia, the country with the largest Muslim population in the world.