Humans communicate a lot non-verbally, thanks to the ability of our brain to understand tone. Would computers be able to do this? Currently capable of understanding plain text, they are struggling to learn the emotions behind the words, conveyed through tone. But these machines are catching up fast. Digital audio processing tools equip computers to understand various information in sound, including emotions.Prof Preeti Rao of the Indian Institute of Technology Bombay is an expert in sound processing—an approach that helps us do various useful things, one of which is removing unwanted sounds (or noise) from an audio clip. With her team at the Digital Audio Processing Lab, Prof Rao attempts to understand the nature of sound, reveal the information it may hold, and use it for, say, identifying tracks, melodies or the raga of a song.