If there were other ships, most likely they would have been non-English speaking ships. Likely that if they did have wireless, their wireless operators were asleep, though most likely they did not because otherwise the wireless operators on the Titanic, Californian, Carpathia, Baltic, Frankfurt, etc would have heard them during the previous day. Naturally, they probably wouldn't have heard of the Titanic's sinking until a week or so later when they reached port and the translated news reached them. At that point it was too late to do anything, and they probably wouldn't have wanted to be drawn into any investigation. They weren't Americans and they weren't British, so they wouldn't have cared about the hearings.