1966

The process of miniaturization continued. Hearing aid components such as acoustic transducers and batteries became smaller and smaller, finally permitting the production of instruments that could be partially concealed inside the ear canal, known as "in-the-ear" (ITE) hearing aids.

Siemens was responsible for the world's first ITE instrument and produced a total of 2500 Siretta 339s.

A noteworthy achievement: In 1974, Siemens celebrated the production of its one-millionth hearing aid.