Critics have noted the differences between Netflix hit “Stranger Things” and “Stranger Things 2,” which bowed Oct. 27, but some things haven’t changed a bit. For example: the post-production setup is the same as before, and nothing if not convenient.

The sound team is based in the Technicolor Seward Post Facility in Hollywood, where members work directly across the hall from the colorist. The convenient positioning allows creators Matt and Ross Duffer to jump between rooms, enabling the merging of picture and sound to inform, even change, aspects of the story.

Brad North, Technicolor supervising sound editor, an Emmy winner for his work on the show’s first season, added breathing sounds during the creation of the gateway between the town of Hawking, Ind., and the so-called Upside Down, resulting in a redesign of the visual effects and one of the show’s signature atmospheres.

Adam Jenkins, Technicolor sound rerecording mixer, a season one Emmy nominee along with fellow Technicolor sound rerecording mixer Joe Barnett notes the power of proximity. “It brings together a boutique idea,” he says.

“Stranger Things” merged details of a rural 1980s town with supernatural occurrences. Over an eight-episode arc, it exploded into a megahit. Feeling the pressure to live up to expectations, the Duffers raised the stakes in season two. For the sound pros, that meant doubling the show’s high level of detail.

They carefully sourced sounds that match ’80s cars, period electrical equipment, even telephone rings. Barnett uses software that can duplicate the frequencies, reverb and other acoustic elements of radio and TV to capture the perfect feel of any element they may have to create, even commercials.

While some authentic ads have been used, the sound team helped fabricate others by recording the voices of crew members, including producer Shawn Levy, altering their vocals and turning them into everything from golf commentators to a choir of angels.

The dialogue in season two presented unique challenges, since the adolescent actors’ voices have changed. To maintain continuity, the sound team would sometimes loop audio or give the actors pitch cues during ADR sessions.

The realism of the supernatural world is equally important. North pulled seal calls to create the show’s Demogorgon monster. Layers of foley design, including walking on dry floors and saturated floors, helped build a major new location in the show. Notes Jenkins: “It’s another way to make it sound more interesting.”