| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 14 |
| # | Industry | |
|---|---|---|
| #1 | Audio-visual technology | |
| #2 | Electrical machinery and energy | |
| #3 | Medical technology | |
| #4 | Machines |
| # | Technology | |
|---|---|---|
| #1 | Loudspeakers and microphones | |
| #2 | Diagnosis and surgery | |
| #3 | Batteries | |
| #4 | Unspecified technologies | |
| #5 | Electric discharge tubes |
| # | Name | Total Patents |
|---|---|---|
| #1 | Cubert Joseph R | 6 |
| #2 | Huth Walter H | 6 |
| #3 | Christ Nicholides Emmanuel | 1 |
| #4 | Ewing Jr Edwin C | 1 |
| #5 | Tittle Hulburt C | 1 |
| Publication | Filing date | Title |
|---|---|---|
| US2395318A | Hearing aid | |
| US2322952A | Hearing aid device | |
| US2308270A | "a" and "b" battery unit | |
| US2304339A | Microphone | |
| US2226281A | Vacuum tube filament | |
| US2239550A | Bone conduction hearing device | |
| US2229206A | Audiometer | |
| US2176671A | A and b battery combination | |
| US2181565A | Microphone | |
| US2156945A | Audiometer | |
| US2186072A | Head phone | |
| US2171793A | Microphone | |
| US2107416A | Electrical sound transmitting and distributing apparatus | |
| US2130206A | Electrical sound transmitter |