Patent ID: 6961591
Filing Date: 2005-11-01
Classification: H04M

Abstract:
1. A handheld telephone set used by connecting an earphone, comprising: a telephone set main body unit; detecting means for detecting which of a dual-ear mount type earphone and a single-ear mount type earphone is mounted to said telephone set main body unit; an amplifier for amplifying an ambient sound and delivering said sound to said earphone; and a control device for adjusting a signal level of said ambient sound output from said amplifier according to an output of said detecting means, wherein when said dual-ear mount type earphone is mounted to said telephone set main body unit a gain of said amplifier is increased to increase said signal level of said sound output from said amplifier, and when said single-ear mount type earphone is mounted to said telephone set main body unit said gain of said amplifier is reduced to decrease said signal level of said sound output from said amplifier.