Starkey Hearing Technologies, the largest hearing aid maker in the United States, has ousted four of its senior executives in a major shake-up of one of Minnesota’s biggest private companies.

Workers at the Eden Prairie-based company received an e-mail Wednesday announcing the termination, effective immediately, of President Jerry Ruzicka, chief financial officer Scott Nelson, operations vice president Keith Guggenberger, and human resources vice president Larry Miller. The e-mail provided no explanation, according to an employee who asked not to be identified.

“We can’t comment due to an ongoing investigation,” company founder and CEO William Austin said in a statement. “There are no issues that affect our company, and it’s business as usual.”

At least one of the executives was escorted from the building by two security workers Wednesday morning, said another company employee, who also requested anonymity.

The names of the four executives were removed from Starkey’s corporate website Wednesday.

A company spokeswoman declined to elaborate, and it could not be determined whether the investigation was internal or external.

None of the four former managers could be reached for comment, despite repeated attempts.

Fred Zimmerman, a retired manufacturing and engineering professor at the University of St. Thomas who follows Twin Cities companies, said the clearing of an entire layer of executives is a drastic step. He called the firings “extremely unusual.”

The management upheaval took Eden Prairie and county officials by surprise.

“They have always been a high-profile corporation and we are very disappointed with this news,” said Eden Prairie Economic Development Manager David Lindahl. “I hope they get it figured out. And hopefully it doesn’t have any significant impact on the business.”

Starkey is well known for expanding its Eden Prairie campus and for its research and development work. It is perhaps best known for the philanthropic work it does globally through the Starkey Foundation. The foundation screens, fits and equips hundreds of poor children and villagers with free hearing aids each year.

Austin founded Starkey in 1970. Ruzicka, a graduate of Minnesota State University, Mankato, joined the firm in 1977 and rose through the ranks, becoming president at age 29. He is credited with helping build the company’s annual revenue from about $8 million to more than $500 million.

Starkey is the fifth-largest hearing aid maker in the world and employs more than 3,600 people in 18 countries.

Starkey’s innovations include the first hearing aids to fit completely into the ear canal and Halo, a hearing aid that can be operated through iPhones and other Apple wireless devices. The company was a pioneer in developing a hearing aid that blocked background noise.

Austin remains Starkey’s CEO. In 2014, the billionaire businessman said he spends most of his time with the Starkey Foundation.

The foundation has attracted well-known guests to its fundraising galas, including former presidents Bill Clinton and George W. Bush and singer Katy Perry.

 

Staff writer Joe Carlson contributed to this story.