 |
| |||
| audible warning system | |||
| voice frequency signaling system | |||
| звуковая система сигнализации: 18 phrases in 10 subjects |
| Astronautics | 2 |
| Automated equipment | 1 |
| Construction | 2 |
| Firefighting and fire-control systems | 2 |
| Military | 1 |
| Mining | 3 |
| Public utilities | 1 |
| Rail transport | 1 |
| Technology | 4 |
| Telecommunications | 1 |