engine hum decelerating between 57-53 mph?

96' Accord LX 160,000. When my car is decelerating between 57-53 mph I get a hum under the engine and a slight vibration in the gas pedal. One guy said it could be the timing belt, but that was replaced 3 months ago. He then said it could be the bearings in timing belt? I checked the parts list on my receipt and all it listed was a timing belt, balancer belt, water pump, and 3 engine seals. Any thoughts?

When idling, I get a higher pitched sound in the timing belt area when I hit the gas. Same guy said that could be the bearings too. What bearings is he talking about. He said bearings should be changed when a timing belt is changed. I called Honda and they never heard of changing bearings with a timing belt.