I have hundreds of video clips shot during a voyage. I process them using Sony Vegas Movie Studio. For each clip I remove the sound track and replace it by my own narration. Then these clips are produced as MPEGs for further processing using DVD Architect. Finally the dvd is created. But when I play the DVD in the majority of the chapters there are audio problems. The voice comes with echos as if somebody is shouting in an immense theatre hall. I examined the audio tracks that cause trouble and the ones that are normal using audacity. They are all stereo 48000 Hz 32 bit floating point. I see no difference between them. I am not an expert on audio. Could someone help please? Thanks.