| 摘要 |
In a hands-free speech communication apparatus incorporating an echo canceler in a mobile telephone, a howling prevention unit for preventing howling caused due to leakage of a mobile-side loudspeaker output voice into a mobile-side microphone input during hands-free speech communication and an echo canceler for canceling an echo generated due to leakage of a transmission voice signal from a self line output terminal into a reception voice signal input to a self line input terminal are constituted by a one-chip digital signal processor. The digital signal processor is controlled by a microprocessor incorporated in an external cellular phone, thereby controlling/processing operation parameters of the howling prevention unit and the echo canceler on the basis of software. <IMAGE> |
