2012 Nissan Altima - Whirrs

Recently I drove 500 miles round trip. I noticed a kind of soft whining noise and it sounded like it never kicked in to gear even at 65 and 70 mph on the Interstate. After returning home and just doing local driving it still sounds like it is not exactly in gear if that makes any sense. What should I be concerned about or have checked ?

You don’t really have “a gear” to switch into. These cars use a continuously variable transmission. They tend to have problems and they need their fluid changed on a regular basis. I’d suggest every 30,000 miles. This 7 year old car is likely way beyond that mileage and if you haven’t had it changed do so now. That might make the noise go away.