| |||
busy signal | |||
engaged tone | |||
busy tone; busy back; busy-back tone | |||
| |||
busy-buzz; busy-tone; busy-back-tone | |||
| |||
line busy tone |
忙音 : 21 phrases in 8 subjects |
Artificial intelligence | 1 |
Communications | 1 |
Electronics | 4 |
General | 1 |
Information technology | 2 |
Programming | 1 |
Technology | 5 |
Telecommunications | 6 |