 |
| |||
| busy tone; engaged tone | |||
| subscriber-busy signal | |||
| busy signal (The indication that the phone is busy) | |||
| busy signal; busy-flash signal; engaged signal; telephone busy signal; line busy tone; slow busy | |||
| "in use" indication | |||
| sinal de ocupado: 4 phrases in 3 subjects |
| Communications | 2 |
| Electronics | 1 |
| Telecommunications | 1 |