I had to have the original inducer fan replaced on my Heil DC90 [NUGM100EHB1 12+ yrs.old] gas furnace because it was dripping water.
The same HVAC company that installed the furnace replaced the inducer with the FASCO A170, and I immediately noticed an unpleasant noise from the inducer fan motor -- a higher pitch like a hair dryer that you can hear throughout my house. The HVAC people replaced the A170 three times (they thought they had a bad batch of noisy "rattling" motors). I finally clarified with the HVAC people that it was not a rattling noise, and they say it's just the normal sound of the inducer running that's creating the noise I hear.
Bottom line is now when my furnace runs there's a constant high pitched noise (almost the tone when you inhale whistle, but it's not an airflow sound). The original inducer fan that began dripping was disposed by the HVAC tech, and it barely made any sound when running.