It's never been 100% determined that the noise was detected was the vessel imploding, so to pull the search on the basis of that alone would have been erroneous.
Even today the USN are cautious in the use of their language when describing the noise that was detected. I daresay it most likely was, but the USN are still cautious enough about the reliability of the detection not to say that it was for sure, and use phrases such as "corresponds with."
Cameron was premature with his statement and presented it with credence that the Navy themselves had not bestowed upon it, and the media were stupid for taking an unsubstantiated 3rd party report as gospel.