Whistling Noise From Air Vents

I've got a 2014 double cab that I just bought about 6 months ago recently I've noticed a whistling noise while I'm driving coming through my air vents. I only hear it usually above 60mph and it gets louder the faster I go. I also notice a tiny amount of air flowing out of my vents even when my A/C and everything is turned off. Is this a common thing or is this something I need to get checked out?

 

Got a recording you can post?

 

My blower gets somewhat noisier the faster I go, I'm assuming air traveling faster through the cowl accelerates or disturbs the spinning of the blower. Slight airflow coming through the vents even with blower off is normal if you are traveling at speed. Also check that you aren't getting wind noise at your driver and passenger door seals. My passenger door seal was particularly noisy until I stuffed it with a section or irrigation line. Now it just makes a small whistling noise on the highway.

 

Is the noise/air flow the same if set to recirculate? If fan is set to ON?

 

You are hearing the outside air coming in through the vent. Turn on air recirculating and the noise will go away.