Telephone having automatic gain control means

摘要

A telephone is disclosed having an automatic gain control circuit and a processor which separates a local signal into a sound signal and a speech signal. The automatic gain control circuit selects a gain value based on sound levels of the sound signal when the speech signal indicates an absence of speech. The telephone also has a variable gain amplifier to amplify a received signal. The gain of the amplifier is selected from stored gain values which are stored in a memory of the telephone in a table format and are a function of the sound signal and volume levels of the sound signal chosen by a user. An input device of the telephone allows the user to select one of the volume levels.