Howling sound from front end when engine under load

What is your question?

Sound comes from front end when under a load, sound starts around 50-60mph. Replaced hubs/wheel bearings about 8months ago. Press the gas pedal the howling can be heard let off the gas howling goes away.

What makes this problem better or worse?

Staying below 50 can't hear it

How long has your 2006 Jeep Commander had this problem?

A few months