Hello, I am using record_session via ESL to record the user/system conversations of a spoken dialogue system. The audio is saved as a wav file. I am also doing the logging from the start of the recording until the user hangs up. I found the recorded audio length is shorter than the time length shown in the log file. Roughly it is 20 seconds shorter in a 10 minutes recording. Googled around, didn't find any clue. ( I did find a similar post which was a year ago and fixed in the newer FS version, I just tried latest FS git head today but still have the same problem as before). Does anybody have any idea about the possible reasons for that? Many thanks! Xing ----- Sunday Times Scottish University of the Year 2011-2013 Top in the UK for student experience Fourth university in the UK and top in Scotland (National Student Survey 2012) We invite research leaders and ambitious early career researchers to join us in leading and driving research in key inter-disciplinary themes. Please see www.hw.ac.uk/researchleaders for further information and how to apply. Heriot-Watt University is a Scottish charity registered under charity number SC000278.