Howling sound from rear end

Hello,

Howling noise from the rear is typically associated with bad wheel bearing(s) or worn rear differential.
The lowering of the vehicle may or may not be associated with the noise.
Keep in mind that the tires can also make a howling noise. When you have lowered the vehicle if the alignment did not get set it could have issues with the camber being off. Which will lead to premature tire wear and noise if it is severe enough.

Here is an article that covers all the typical hawing noise issues:

https://www.2carpros.com/articles/car-howling-noise

Please let me know of any questions.
Thank you.