Welcome to the World Tone Database, dedicated to the A-Z of international call progress tones. From here you can research tone parameters in national tone plans and hear the tones on-line.
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| Country | Tone | Frequency/Hz | Cadence/s | Audio |
| Singapore | Acceptance tone | 425 | 0.125 on 0.125 off |  |
| Singapore | Busy tone | 425 | 0.75 on 0.75 off | |
| Singapore | Call waiting tone | 425 | 0.3 on 0.2 off 0.3 on 3.2 off | |
| Singapore | Congestion tone | |||
| Singapore | Dial tone | |||
| Singapore | Disconnect tone | |||
| Singapore | Holding tone | |||
| Singapore | Holding tone | |||
| Singapore | Holding tone | |||
| Singapore | Holding tone | |||
| Singapore | Intrusion tone | |||
| Singapore | Number unobtainable tone | |||
| Singapore | Ringing tone | |||
| Singapore | Second dial tone | |||
| Singapore | Warning tone | |||
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