The stock of little-known IntriCon, maker of lower-cost hearing aids and other tiny medical devices, surged by nearly 30 percent in value last week amid huge trading volume as buyers warmed to its financial outlook and recent favorable federal legislation. .

As a result, the Arden Hills-based company is trading at its highest prices in nearly a decade.

On Tuesday alone, "IIN" closed up nearly 10 percent to $11.25 per share, on volume that ranged from five times to 20 times normal trading levels for a company that had traded less than 10,000 shares daily on average.

The brass at IntriCon, which is now valued at nearly $80 million, aren't sure who was buying the stock.

"We are always out talking to new investors," said longtime CEO Mark Gorder. "We raised about $4 million last year and brought in Heartland Funds. But we know it's not those folks buying.

"More people seem interested in the logic of what we are doing and the [recent federal] law adds credibility."

Employees at IntriCon work to manufacture and assemble hearing aids at the company’s plant in Arden Hills.

In late August, President Donald Trump signed the U.S. Food and Drug Administration Reauthorization Act, which includes a provision that allows adults with mild to moderate hearing loss to access over-the-counter hearing aids without being seen by a hearing care professional.

Several of the world's largest hearing aid companies, which dominate the hearing market and also are at least partial owners of thousands of retail audiologist shops, opposed the legislation. That includes Twin Cities-based Starkey Hearing Technologies and the locally based North American headquarters of Amplifon and ReSound. They sell hearing aids under various brand names.

Gorder and others who want to disrupt the industry argued that about 10 percent of the people served by the $11 billion hearing aid industry in the United States can be served with lower-cost, innovative products sold directly to consumers that also will spur competition.

The bill passed Congress with bipartisan support.

IntriCon last month reported a small second-quarter profit on net sales of $22 million, up 32 percent from the same period in 2016.

That included a 46 percent increase in sales of electronic products that it manufactures for Medtronic, including a wireless glucose monitoring system.

The hearing health business sales grew 32.5 percent from the second quarter of 2016.

IntriCon has made a series of investments in hearing technology that the company says are bearing fruit.

"Gains in medical and value hearing health are driving strong performance and we expect that to continue in the third quarter," Gorder told investors last month. "In addition we're making meaningful progress in creating and cultivating a new channel to deliver superior, outcomes-based affordable hearing health care directly to consumers."

IntriCon added to its position in the hearing industry through its purchase late last year of a stake in Illinois-based Hearing Help Express (HHE), a direct-to-consumer mail order hearing aid provider. It has exercised an option to purchase the rest of the company this year in a deal to close by year's end. That business is expected to grow by 35 percent in the second half of this year.

Moreover, IntriCon has struck an agreement to acquire 49 percent of Soundperience of Germany, which has designed the first "psycho-accoustic" way of analyzing peripheral hearing and central hearing processing through its Sentibo software.

That is being integrated with IntriCon's wireless hearing aids that will be rolled out in Germany this fall. Gorder said the Sentibo software technology also will be critical to its domestic value-based hearing health care model.

The company says Sentibo, and its other fitting systems, are designed to improve both distribution productivity and the quality of first-time fittings, resulting in lower prices, wider access and greater customer satisfaction.

Gorder said in an interview last week that IntriCon is holding to its August statement to investors that it expects to be profitable this year on record sales of up to $88 million. That would be a 33 percent increase over last year.

Gorder, 70, an electrical engineer and MBA out of the University of Minnesota, joined a privately held predecessor company to IntriCon in 1977.

"We have never been better positioned for growth," Gorder told ­investors recently.