I have a 2013 accord 2.4. There is a whining coming from the engine compartment/dash? It only occurs at low speed acceleration and tapers off as acceleration decreases. What?

 

Welcome to the forum. Possible tension bearing. Or transmission gears.

 

Welcome in,I agree ,could be a belt tensioner. Take a large screwdriver and with the engine running place the handle to your ear and the metal tip to the tensioner acting like a stethoscope listen for any grinding or whining in the area,you will also feel the vibration that way.