New Delhi, Aug. 9 -- What began as a PhD student's frustration while watching Spanish films in the United States three decades ago has today evolved into a nationwide literacy movement that is shaping India's broadcasting policy on subtitling.

In an interview with Mint, Brij Kothari, who leads BIRD, or the Billion Readers initiative, traces the remarkable three-decade journey of Same Language Subtitling (SLS), the idea of displaying subtitles in the same language as the audio, such as Hindi subtitles on Hindi films or Tamil subtitles on Tamil programmes.

Today, after years of resistance, research and policy advocacy, over 110 television programmes in India carry SLS, reaching an estimated 160 million viewers, Kothari says. The initiativ...