Cicierega began work on the mixtape after discovering multiple raw instrument tracks from songs featured on the music video game series Rock Band.

Later on, the song "No Credit Card" (a remix of Huey Lewis and the News' "The Power of Love") appeared on Neil Cicierega's SoundCloud account on February 6, 2013.

[4] In addition, Cicierega posted a music video for "The Sharpest Tool" (titled "MOUTH") to his main YouTube channel a year earlier on February 9, 2013.

Club, called the mixtape "brilliant," citing its ability to toy with the listener's nostalgia held towards the songs included, and wrapped up her review by suggesting the album to those that enjoy the thought of "dropping acid at a Media Play going-out-of-business sale.

"[6] Ben Simon of Music Putty also wrote of Mouth Sounds' ability to relate to the listener's childhood memories, writing, "nostalgia is the album’s unifying theme," and citing the third track, "D'oh," as an example of when it "is taken to its most equally incredible and horrific extreme.