Issued Patents 1994
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5343523 | Telephone headset structure for reducing ambient noise | Charles S. Bartlett, Roger David Benning, John Bradley Hunter | 1994-08-30 |
| 5325438 | Active noise-cancellation system for automotive mufflers | Douglas R. Browning | 1994-06-28 |