National service planned, developed and operated by the Prasar Bharati Broadcasting Corporation of India. Sound broadcasting started in India in 1927 with the proliferation of private radio clubs. AIR today has a network of 237 broadcasting centers with 149 medium frequency (MW), 54 high frequency (SW) and 177 FM transmitters. The coverage is 91.85% of the area, serving 99.18% of the people in the largest democracy of the world. AIR covers 24 Languages and 146 dialects in home services. In External services, it covers 27 languages; 17 national and 10 foreign languages.