| 2646465 | N/A | 1953-07-21 | ||
| 2613273 | Speech wave analysis | 1952-10-07 | ||
| 2602836 | Instantaneous frequency analyzer | 1952-07-08 | ||
| 2575909 | Voice-operated system | 1951-11-20 | ||
| 2375044 | Selecting system | 1945-05-01 | ||
| 2195081 | Sound printing mechanism | 1940-03-26 | ||
| 2137888 | Means and method for converting speech into visible indicia | 1938-11-22 |