I think I'm going crazy here. Yesterday I was working in my computer and several times I heard 3-4 repetitions of what seems to be a cellphone in vibration mode. I checked my cell and I asked my son several times if he was receiving text messages. He said no and added that the vibration feature on his phone was not working anyways. I had to let it go because I was starting to get annoyed by the situation, but then, when I was in bed like around 11pm, I was watching tv and once again the same noise happened exactly like a cellphone. Three repetitions of a vibration and then stopped. I put my tv on pause and ran to my son's room which shares a wall with mine and asked him if he had received a message and I got the same answer and explanation I got through out the day, no incoming messages and feature broken on the cell. I told my husband what was happening and he reminded me that our next door neighbor was hearing the same noise and once he thought that somebody was in his backyard and the cellphone went off. He checked, but nothing. What can it be? It's annoying to hear something like that and not know whats causing it. Help please! Thanks!