I have always time stamped my video and audio. When I start a session and end a session I always say the time. In fact one thing that I have also always done is tag everything that I can. If you tag properly and record the time with every session you really don't have to exactly synchronize your video and audio together. Reason being, if you start your audio at 9:05 and then start your camera at 9:12 (verbally stating the time once recording begins on either device) you already know one starts 7 min. after the other. Plus when going room to room, if you hear or see something you always tag it then "heard unexplained thump at 10:22". Synchronizing is nice when you can do it, but not necessary when proper tagging and stamping is done. If you work with small team you can even designate someone as the recorder for the evening. Their job is to take notes the entire time. This way they can record all pertinent information. If your on separate floors you can radio to them and the group what time something started or what time something was heard or witnessed. I also keep notes from cases I've done......let's say you wanted to know when a picture of a shadow figure was taken in the basement of local house I did 8 years ago. I could go back right now dig up the files and notes and I could tell you. I do agree with you, synchronizing your equipment when you can is extremely useful.