A method for controlling volume in an apparatus having a speaker and a microphone includes receiving, at the microphone, external noise and speech of a user, and calculating sound pressure of the noise received by the microphone. The method further includes performing exception processing of the sound pressure of some or all of the noise using the calculated sound pressure and one of a speech utterance state, a speech receiving state, or a temporal length state, of the noise, mapping volume of the speech in response to the sound pressure of the external noise, synthesizing speech guidance into a sound file, outputting the sound file, via the speaker, according to the mapped volume.