Imam al-Baqer (a) narrates some of the events that occurred in Karbala and Shaam. He was 4 years old according to a hadith by him. I have not seen any hadiths that state he spoke to Yazid, probably because the Imam was only 4 and so Yazid would not speak to a child or respond to a child. And with the presence of Imam Zainul Abidin (a), there was no need for him to talk.