Though Kamal Haasan is a man of many talents and can speak many languages, a lot of times, SP Balasubrahmanyam had dubbed for the star's Telugu dubbed films, a tradition that started with K Balachander's Manmatha Leelai.
SPB had dubbed for seven of the 10 characters played by Kamal in the Telugu version of Dasavathaaram including a female character. Here's a clipping of him demonstrating live how he did and look how the audiences look spellbound. We too, for that matter.
He has also dubbed for Nandamuri Balakrishna for the Tamil version of Sri Rama Rajyam in 2012 and Ben Kingsley in the Telugu-dubbed version of Gandhi.
Besides the above-mentioned heroes, he has dubbed for Rajinikanth, Vishnuvardhan, Salman Khan, K. Bhagyaraj, Mohan, Anil Kapoor, Girish Karnad, Gemini Ganesan, Arjun Sarja, Nagesh, Karthik, and Raghuvaran in various languages.