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.
Business customers subscribing to our paid premium service can benefit from unrestricted searching of over 1,700 records, update notifications and support, for up to ten users, ad-free.
Help us improve! If you have updated information on Disconnect tones or official versions of national tone plans, please let us know.
| Country | Tone | Frequency/Hz | Cadence/s | Audio |
| Angola | Busy tone | 400 | 0.5 on 0.5 off |  |
| Angola | Congestion tone | 400 | 0.5 on 0.5 off | |
| Angola | Dial tone | 400 | continuous | |
| Angola | Number unobtainable tone | |||
| Angola | Ringing tone | |||
| Angola | Waiting tone | |||
Corporate user? Please consider sponsoring this service by getting a paid subscription for your institution.