| Number | Name | Date | Kind |
|---|---|---|---|
| 3029553 | Clemens | Apr 1962 | |
| 3121293 | Sperry et al. | Feb 1964 | |
| 3165860 | Glass et al. | Jan 1965 | |
| 3425156 | Field | Feb 1969 | |
| 3884317 | Kinzel | May 1975 | |
| 4516647 | Novak | May 1985 | |
| 4735592 | Griffin | Apr 1988 | |
| 4875885 | Johnson | Oct 1989 | |
| 4932913 | Raviv et al. | Jun 1990 | |
| 5045016 | Stern et al. | Sep 1991 | |
| 5195920 | Collier | Mar 1993 |
| Number | Date | Country |
|---|---|---|
| 2654861 | May 1991 | FRX |
| 1010685 | Nov 1965 | GBX |
| Entry |
|---|
| Texas Instruments, Complex Sound Generator SN 76477 Jul. 1978. |