| 摘要 |
PURPOSE: An apparatus for detecting a call connection according to a transmission call in a communication terminal and method are provided to inform a call line connection by a call transmission to user and inform a busy signal by a call transmission to user. CONSTITUTION: An apparatus for detecting a call connection includes a first band pass filter(161), a second band pass filter(163), a third filter, and a control part. The first band pass filter is to pass 440Hz band of a voice signal being inputted to a speaker. The second band pass filter is to pass 660Hz band. The third filter is to cut a frequency more than 440Hz. The control part is to judge a connection state of a call path by whether a signal being offered an output from the first band pass filter, the second band pass filter, and the third filter is or not.
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