| |||
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 |