Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5500901 | Frequency response adjusting device | Donald R. Hagen, Arman E. Sundquist | 1996-03-19 |
| 5001762 | Miniature modular volume control and integrated circuit assembly for use with a hearing air | David Barwig | 1991-03-19 |