
Envoy Medical Corp. hopes to raise $6.0 million in an equity-based round, according to documents filed with the Securities & Exchange Commission.
The White Bear Lake, Minn.-based company is the maker of Esteem, an implantable hearing aid with no readily visible external components.
The FDA approved the Esteem in March 2010.

The device, which is implanted behind the ear, requires invasive surgery and costs $30,000. Unlike traditional hearing aids, which amplify sounds with microphones, the Esteem converts eardrum-sensed vibrations into electronic signals, cleans them up with a sound processor and then converts them back into mechanical sounds.
Envoy has had many big-name investors, including Minnesota Timberwolves owner Glen Taylor and former Medtronic Inc. (NYSE:MDT) vice chairman Greg Nelson. A funding round that the company opened last May brought in $16.4 million for the device, which included $10 million from Starkey Laboratories, after a plug from conservative radio talk show host Rush Limbaugh.
Envoy CEO Patrick Spearman did not immediately return a phone call.