Recorder warning tone

In telecommunication, a recorder warning tone is a tone transmitted over a telephone line to indicate to the called party that the calling party is recording the conversation.

In the US, the recorder warning tone is a half-second burst of 1400 Hz applied every 15 seconds. The recorder warning tone is required by law to be generated as an integral part of any recording device used for the purpose and is required to be not under the control of the calling party. The tone is recorded together with the conversation.

References

•  This article incorporates public domain material from the General Services Administration document "Federal Standard 1037C".

External links

• Recorder warning tone defined in Federal Standard 1037C