Sound designers and mixers are asked to add to onscreen realism with audible cues unique to each situation. These audio pros bring their own sensibilities, obviously, but it’s interesting to compare how each works in related genres.

So, Variety checked in with six to hear how they accomplished that goal.

Sweeney Todd: The Demon Barber of Fleet Street” and “Hairspray”

Typically a film’s music score is called on to convey emotions, from happiness to sadness, tension to whimsy in the background. During a full-fledged musical, though, characters break into song to push the narrative, offer insight or create a different mood.

This year “Sweeney Todd” and “Hairspray,” while both musicals, take completely different approaches to music as a narrative tool. While “Hairspray” goes whimsical with choreographed dance routines, “Sweeney Todd” sticks to a more operatic approach, where the characters shift between dialogue and song seamlessly.

Michael Semanick, sound re-recording mixer on “Sweeney Todd,” worked on an early version of “Hairspray.” So, he knows the difference firsthand.

“In ‘Hairspray,’ you’ve got musical numbers. It’s upbeat and fun. ‘Sweeney Todd,’ on the other hand, was much more integrated into the storyline,” he says.

True, says “Hairspray” sound re-recording mixer Rick Kline, but that doesn’t mean the goal was to pull the viewer out of the film to tell the story.

“Obviously, in a musical, you’re in and out of reality and suspended reality, and you want to make that as seamless as possible,” he says. “You don’t want it to feel like you’ve toggled (the music) on and off. Hopefully the audience isn’t aware of the transition.”

While the musical scenes in “Hairspray” are clearly delineated from the rest of the action, “Sweeney Todd” director Tim Burton, Semanick reports, was vocal about avoiding the appearance of a needle-drop music feeling during the film.

Perhaps one of the things that made that work on “Sweeney Todd” was the careful use of Foley and sound effects. Both were played realistically during “Sweeney Todd,” while during the musical moments of “Hairspray” both were used to propel rhythm and meter.

“Bee Movie” and “Ratatouille”

There was a time when animated films or television shows were chockful of cartoony effects that conveyed impossible humor. That’s no longer true, reports multiple Oscar-winning sound designer and mixer Randy Thom.

“Most of the directors that I work with use the word cartoony as a pejorative term,” he says. “They want their films to sound more or less like live-action films.”

Thom was pressed into providing just that feel while working on both “Bee Movie” and “Ratatouille” over the past year with his Skywalker Sound compatriot Williams Files.

Yet Thom and Files also had the opportunity to create exaggerated tracks for both when the concept of perspective needed to be aurally demonstrated. For instance, the first time “Bee Movie’s” Barry B. Benson experiences the human world, everything had to sound huge.

“All the footsteps sound like dinosaurs, and a ball rolling sounds like a boulder,” Files says. “That’s the dramatic impact of how it’s feeling to him to be out in this world for the first time.”

The same happens to Remy, the main character in “Ratatouille” when he drops into Gusteau’s kitchen for the first time. “When Remy has these moments of terror running around the kitchen, certain sounds were accentuated,” Files reports.

Even while the same basic team worked on both films, there was no sonic overlap, and making the films sound unique was easy. “Obviously, you don’t use the same sounds,” Thom reports, “but really the way a film sounds is determined more than anything else by the overall design of the movie. The two movies have very different visual designs and storytelling mechanisms.”

“Beowulf” and “300”

Films that delve into fantasy worlds are a treat to work on for both visual and audio pros. After all, beyond animation, this is the only genre where truly anything is possible, and imaginations are encouraged to run wild.

Supervising sound editor Dennis Leonard experienced that a number of times while working on “Beowulf.” However, Leonard is quick to add, these scenes have to be rooted in aural authenticity.

He points to the scene where Grendel is decapitated by a lightning bolt shot by his mother. “We used very natural thunder and lightning elements, trying to stay inside the film and not try to have any sound effect come forward and dominate one’s consciousness. The best soundtrack is one that is not noticed,” he says.

In fact, taking the viewer out of the “bubble of believability,” as Leonard says, was the key to the film’s sonic success. “The direction we went in was to be as naturalistic as possible, which is kind of hard when you have magical and mystical events happening.”

Scott Hecker, supervising sound editor on “300,” faced that issue during an early scene in the film when a young Leonidas battles a terrifying wolf. “That thing looked so gnarly that we had to make it sound even gnarlier than your average wolf,” he says.

That meant blending sounds from wolves, coyotes, bears and lions, along with human vocalizations. “Our focus was to make it very real, but surreal at the same time.”

He borrowed that idea a few scenes later when the Spartan soldiers were waiting in a wheat field before leaving to battle the Persians. The background of fields and roiling dark clouds set a certain mood. “We used darkly toned winds and things that were emotionally evocative of that moment.”