Let me tell you about a seemingly silly test I did to determine where a similar noise was coming from on my '92 Bonne. I was sure I was hearing a wheel hub bearing going South but I could not tell which wheel it was coming from.
Using some Yankee engine-uity I duct taped, in turn, (don't you just love that stuff) a micro palm voice recorder to each wheel assembly. Can't remember exactly where but as I recall it was no problem to find a spot. Anyway I started with the driver'* side, turned the little feller to RECORD and took her for a ride down the street and back. For the second run I taped the recorder to the passenger side. Finally I listened to each recording. I could definitely tell then which hub was the culprit by comparing the volumn and type of noise generated from each side.
Worked for me!
2001 SSEi- black; stock 92K
1995 Vette; Competition Yellow; stock; 38K