That doesn’t seem to be the case. According to Wikipedia (and other sources too):

Sennheiser’s consumer audio division was acquired by Sonova Holding AG in May 2021.

and

Sonova Holding AG is an internationally active Swiss group of companies headquartered in Stäfa that specializes in hearing care. The Sonova group operates through its core business brands Phonak, Unitron, Advanced Bionics, AudioNova and Sennheiser (Licensed). It is one of the largest providers in the sector worldwide.