To hear Ron Bochar tell it, sound designers, supervising sound editors and re-recording mixers need the same attitude as umpires at a baseball game.

“You try to be the guy that people never mention when they walk out of the theater,” says Bochar, the supervising sound editor and re-recording mixer on “Doubt.”

Yet many directors are rejecting music in favor of subtle sound effects to reveal a character’s state of mind, signal a change in a story’s narrative or preview a plot point.

That shift of philosophy, from sound objectively supporting the action onscreen to subjectively adding tension to a scene or even sending subliminal messages, presents some tricky challenges for sound pros.

Dominick Tavella, re-recording mixer on “The Wrestler,” faced a handful of scenes in which director Darren Aronofsky called for an obvious and dramatic soundtrack, including a heart attack scene and the final scene’s crowd reaching fever pitch. Both called on the sound mix to convey the thoughts of Mickey Rourke’s character, Randy “the Ram” Robinson.

The technique is even more pronounced in the scene in which Randy walks through the grocery store stockroom to his new day job at the deli counter. The soundtrack builds from the natural sounds of the stockroom to a crowd’s roar — the roar Randy knows from entering an arena to wrestle — as the viewer is taken inside the head of the Ram.

Even as Tavella was given free reign to punch up those very subjective moments, he still had to stick to the film’s gritty, naturalistic style. “The film is very grounded in Randy’s life as it was going on day to day,” he explains, “and it’s shot almost in a cinema verite style. This wasn’t a fantasy structure with a lot of strange things going on.”

In the case of “Doubt,” Bochar utilized wind sounds to add a layer of metaphor to John Patrick Shanley’s adaptation of his stage play.

“It was one of the conventions of the film that was written into the screenplay,” he explains. “The winds of change. A storm is coming.”

At the same time, he adds, “We didn’t want to make it into such a motif that it became too obvious. You want it to be part of the ambiance, and you don’t want it to be like as soon as (Meryl Streep’s character) says something, wind starts whipping around.”

The Clint Eastwood-directed “Changeling” boasted an uber-authentic soundtrack except for three key scenes when the sound design was punched up to heighten the drama, including the Gordon Northcott execution scene in which the sound of the rope tightening around his neck played prominently.

While supervising sound editor Allan Robert Murray was able to play up those elements, he admits the direction was to remain in the realm of the possible.

“You don’t want to overpower the film, but you want to draw the audience in,” he says. “There are certain moments where you feel like you want to make a point and you’ve definitely got lines to work in, but I think you can cross them a little.”

Even when the effects mix stays firmly in the realm of the objective, though, it’s possible to make the experience almost hyper-real.

In “The Curious Case of Benjamin Button,” for example, supervising sound editor and re-recording mixer Ren Klyce says for scenes with Brad Pitt and Tilda Swinton in the Russian hotel, “We tried to make every little thing special, from the sound of the vodka bottle being opened to the mouth pops when they are eating caviar. Sure it sounds like that, but we added all that in and exaggerated it so the audience could feel like they were having that experience.”

There is a danger in that approach, though. “You can inadvertently start steering the audience to feel things emotionally, particularly if you put a big music cue in front of the scene,” he explains. “Some filmmakers want to do that, but (‘Button’ helmer David) Fincher wants the audience to be curious the whole way.”

Helping the audience stay invested, Klyce says, is ultimately the reason that barrier gets broken. “Our job is to guide them through the story,” he says. “I like to think they are not aware of it and couldn’t point it out, but we can set the mood and give them auditory reveals to any scene.”