SAN FRANCISCO (AFP) -- Shazam has announced that 100 million people use its song-recognition mobile service monthly -- a 34-per-cent surge from a year earlier.

Shazam applications have been downloaded to more than 500 million mobile devices since the the 1999 launch of the firm, which said Wednesday it was adding users at the rate of 13 million monthly.

The applications let people identify songs, television shows or even some ads by "listening" and then provides opportunities to make purchases or link to online content related to what was heard.

"Shazam is evolving from being a way to identify a song to a way for people to explore and connect with the world around them," chief executive Rich Riley said in a statement.

"Shazam now delivers a deeper discovery and content experience for music and TV, with retail, cinema and more coming soon."