Noise when hitting gas

Let me start by saying I am not the least bit knowledgeable with it comes to truck mechanics, nor do I try to pretend like I know wtf I am talking about. With that being said, when I hit my gas pedal on my 17 Tacoma I can hear a hissing noise. Is that normal? Fuel injection maybe? I've also realized I get a weird rattle noise on the highway from under the hood at times but only after drives of 30+ minutes. Anyone have any insight for this noob?

 

Combination of high pressure direct injector noise, special injector cleaning cycle (ticking at idle periodically), and a flapper inside the intake which varies the intake runner dimensions based on RPM an load. Lots of stuff going on, and normal.

 

Thanks!

 

Rattlesnake under the hood?