| 摘要 |
A user-authentication system includes an AUD for transmission of dtmf tones to a user-verification system over a telephone network. In a memory module of the AUD, voice and access data are stored for subsequent transmission to a user-verification system. A compensating system associated with the AUD generates two low frequency and two high frequency tones, and selectively amplifies them to varying levels to compensate for transmission efficiencies associated with conventional telephone microphones. The user-verification system further detects unauthorized users, and includes memory storing data relating to access numbers used, and a user's voice, a transmitter transmitting a first signal requesting voice information and a second signal relating to time, a receiver receiving the tones and the signal relating to time, and an analyzer device determining whether the access number used to reach the user-verification system is identical to previous access numbers used, whether the signal relating to time corresponds to the time of user-transmission of the tones, and whether the user's voice corresponds to the stored data. A system for routing a tone signal from the AUD to an intended user-verification system includes a central switch receiving tones from the AUD including an initial alert tone followed by data tones representing voice-related and destination-related data. The central switch includes an analyzer device analyzing the tones, and a routing device routing the tones to a user-verification system in response to the alert tone. A system for performing amplitude equalization associated with each of the user-verification systems has a receiver receiving tones relating to a user's voice, an amplifier generating an amplification factor for each of the tones, and a correcting device using the amplification factors to correct subsequent voice tones. |
