Sonova said it made the 200 million euro ($241 million) deal to expand its ageing demographic to younger customers, particularly in the wireless in-ear segment.
"Even if they don't have hearing loss, most of them will gradually get hearing loss with age, and devices like Sennheiser's allow us to have earlier consumer access to such people", Sonova chief Arnd Kaldowski told Reuters.
The company said it would build on Sennheiser's HiFi expertise and "combine it with its own technology expertise and strengths in the field of innovative hearing solutions".
As part of what the company called a "partnership", Sennheiser will completely transfer its consumer business to Sonova.
Sennheiser said it had 600 employees in its consumer division, but made no mention of possible layoffs.
Sennheiser's Co-CEOs, Andreas and Daniel Sennheise,r said Sonova "not only shares our passion for audio and a commitment to the highest product quality, but also very similar corporate values". Sonova will gain permanent licensing to the Sennheiser brand, giving it an entry into the consumer headphone segment.
"Combining our audiological expertise with Sennheiser's know-how in sound delivery, their great reputation, as well as their high-quality products, will allow us to expand our offering."