This study focuses on Switchboard-300, a standard 300-hour English conversational speech recognition task. As a contrast to our best results on Switchboard-300, we also train a seq2seq model on the 2000-hour Switchboard+Fisher data.  
 Question: How much bigger is Switchboard-2000 than Switchboard-300 database?
Switchboard-2000 contains 1700 more hours of speech data.