SANTA CLARA (AP) — Jim Harbaugh will turn to lip reading, motioning and even sign language if he has to in order to communicate with Colin Kaepernick to keep things running smoothly in the deafening noise of Seattle’s home stadium.

Kaepernick plans to repeat his calls as many times as necessary in the huddle during the NFC championship game Sunday to make sure his teammates hear him.

“He just has to be louder,” center Jonathan Goodwin said. “There’s really no special tricks. You’ve just got to be as loud as possible and hope everybody hears it.”

Solid communication through the chaos at CenturyLink Field will be paramount for Kaepernick, who had one of his worst performances as a pro in a 29-3 Week 2 loss to the Seahawks.

In preparation, music blared across San Francisco’s practice field Wednesday. The 49ers regularly practice with the sound system at full blast, but it is that much more important this week as they head to what is considered the NFL’s loudest venue.

“Other teams may approach it differently,” Harbaugh said. “You’ve got to be able to communicate without being able to hear very well. You can simulate that somewhat in practice. Signals, hand signals, verbal signals, body language, reading lips, different ways. But, we’ll practice that. We’ve been in some of those environments.”

While Kaepernick blames poor execution, and not noise issues, for two disappointing defeats in Seattle over the past 13 months, he realizes he will have to holler at the top of his lungs to avoid further problems getting the snap off in time.

“You stick to the basics,” wideout Anquan Boldin said Wednesday.

The 49ers (14-4) had the second-most delay of game penalties in the NFL during the regular season with eight and have frequently struggled to get plays off on time, forcing them to waste timeouts.

And that’s in the best of circumstances, not in the Seattle noise. In the first meeting with the Seahawks, the Niners committed two false starts, one delay of game and needed to use two timeouts on one third-quarter drive as they fought the play clock. Last year, they had two delays and were again forced to use two timeouts on offense when they couldn’t get the play off.

San Francisco had similar problems in its wild-card win at Green Bay two weeks ago.

In the 49ers’ Sept. 15 road loss to the Seahawks, Kaepernick threw three interceptions and completed only 13 of 28 passes for 127 yards for a career-worst 20.1 passer rating. He also took three sacks. And on Dec. 23, 2012, at Seattle, Kaepernick went 19 of 36 for 244 yards with a touchdown, one interception and a sack in a 42-13 defeat.

In all, the 49ers have committed seven turnovers and been outscored 71-16 in their last two trips to Seattle.

“We do have to protect the football. That’s something we haven’t done very well up there. I think going into this game we have to make sure we do that so we can come out with a win,” the quarterback said. “It’s a different game. It’s a whole separate entity. It’s a little bit louder in Seattle.”

More than a little bit louder, really.

Seattle gets so loud, in fact, not only does it help cause tremors, but place kicker Phil Dawson can’t even hear when his foot makes contact with the ball.

“There’s no comparison,” defensive tackle Ray McDonald said. “Playing in college, NFL, that’s the loudest stadium I’ve ever played in. I can see why it gives offenses trouble, it’s just so loud you can’t really make the checks you want to.”

Cornerback Carlos Rogers has one answer to bringing down the noise level.

“Once we start winning, the first points on the board, that will take all the fans out of it,” said Rogers, who participated in his first practice after missing the last two playoff games with a strained right hamstring.

The 49ers have already won at bitter cold Green Bay and at Carolina in the NFC divisional playoff round last week, and they know this is another challenging step in their quest for a return trip to the Super Bowl to chase the franchise’s sixth championship.

And when it comes to Seattle’s raucous “12th man” crowd, which even affects the home team at times, Kaepernick offers a gentle reminder.

“We only have 11 on the field,” he said, “just like them.”