| 主权项 |
1. A method of detecting voicemail greetings using voicemail fingerprints, the method comprising:
storing, for each one of a plurality of top level telephone numbers, i) a corresponding forwarding telephone number, and ii) a corresponding secondary forwarding destination; for each one of the forwarding telephone numbers, storing a voicemail fingerprint of a known voicemail greeting, the voicemail fingerprint made up of a plurality of audio analysis streams, each one of the audio analysis streams containing audio characteristics of the known voicemail greeting associated with the forwarding telephone number beginning from a respective one of a plurality of different temporal offsets from the beginning of the known voicemail greeting; in response to receipt of a call to one of the top level telephone numbers, i) initiating a call to the forwarding telephone number corresponding to the top level telephone number, and ii) performing a voicemail detection operation by a) generating a current audio analysis stream containing audio characteristics of audio received beginning when the call to the forwarding telephone number is answered, b) comparing the current audio analysis stream to each one of the audio analysis streams in the voicemail fingerprint of the known voicemail greeting associated with the forwarding telephone number, and c) in response to detecting that the current audio analysis stream matches one of the audio analysis streams contained in the voicemail fingerprint for the known voicemail greeting associated with the forwarding telephone number, detecting that the call to the forwarding telephone number has been answered by a voicemail box of the forwarding telephone number; and in response to detecting that the call to the forwarding telephone number has been answered by the voicemail box of the forwarding telephone number, transferring the received call to the secondary destination corresponding to the top level telephone number. |
