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 |
Sierra Leone | Busy tone | 425 | 0.5 on 0.5 off | |
Sierra Leone | Busy tone | 450 | 0.5 on 0.5 off | |
Sierra Leone | Congestion tone | 425 | 0.2 on 0.2 off | |
Sierra Leone | Dial tone | |||
Sierra Leone | Dial tone | |||
Sierra Leone | Number unobtainable tone | |||
Sierra Leone | Number unobtainable tone | |||
Sierra Leone | Ringing tone | |||
Sierra Leone | Ringing tone | |||
Sierra Leone | Waiting tone |