I have been doing some research on how to turn the engine noise off and have come across info that fuse 27 on the 2015 mustangs shuts off the fake engine noise. In the mustang user manuals it states that fuse 27 is used for 'amplifier' which is assumed to be just the engine noise amplifier. That being said I looked in the F150 user manual and the fuse labeled amplifier is fuse 14. Assuming it's the same as the mustangs pulling fuse 14 should shut off the fake engine noise and not anything else. I haven't tested this since I do not have a 2015 ecoboost but was wondering if anyone else would be willing to verify whether or not this works.
This is the video where I got my info for the mustang:

 

Someone needs to try this!

 

X2

 

Anyone with a 2015 ecoboost wanna help out?

 

Where is the fuse box

 

I believe in the passenger side foot well.

 

If it was not pouring rain outside right now I would go give it a try. Even if it works I'll be putting the fuse back in. I like the augmented sound.

 

I will be trying this first thing in the morning.

 

Going to try it right now if I can find the fuse box.

 

So yes it does shut off the fake engine noise by pulling fuse 14. It also shuts off your entire audio system and you get no sound at all. So that fuse is for your audio amplifiers (makes sense being 20 amps), not a discrete fake engine sound generator.

Fuse 14 is in the fuse block under the hood. There is also a fuse block on the passenger side foot area (right kick panel).

#FAIL