The ringing in Tyler Eifert's head last week was the result of a collision between two football players.
The ringing in Eifert's head this week - a much clearer head than it in the second half against Purdue - is the signal that something big will be happening in Spartan Stadium Saturday night.
"This is a huge game," said Eifert, who has caught a team-leading eight passes for 120 yards and a touchdown in the first two games of the 2012 season.
"I keep seeing the preview for it on ABC and it gets me pretty excited. They're always a good team."
Eifert is happy to be back after a block in the Purdue game rung his bell, ultimately prompting him to miss a significant portion of the second half as the Irish scrambled to survive in a 20-17 victory over the Boilermakers.
"I didn't take any big hits, but I was throwing a block," Eifert said. "It was like a crackback and it was just a big collision. He saw it coming and it was just two big guys running into each other.
"I was in for like three more plays after it happened, and I came off and some of the guys noticed that I wasn't right and grabbed the trainer. I didn't feel right during those plays. I was unsure of the plays that I was actually in after I had the collision, but I remember everything else."
Eifert's recollection includes the solid play of Everett Golson throughout most of the game, followed by the heroics of Tommy Rees on the game-winning drive.
"Everett played a great game," Eifert said. "I don't know exactly what his numbers were, but they were pretty good. Tommy came in, and he's done that before on those two-minute drives. He's good at that."
Before Notre Dame's medical staff will clear a player of a head injury, he must pass some "baseline" tests that are predicated on standard inquiries made prior to the start of the season.
"They test your reaction time and accuracy and how well you remember things," Eifert said. "I passed all of those tests (Sunday)."
Speaking of tests, there will be none bigger in college football Saturday as the No. 10 Spartans square off with the No. 20 Irish. The home team has won four straight in the series after the visiting team won seven in a row.
"They're a solid Big Ten opponent and it's always going to be a good game when we play them," said Eifert, who caught just two passes for 25 yards in Notre Dame's 31-13 victory over the Spartans last season.
"It's always a dogfight with Michigan State. We're expecting another game like that."