When you dream of the intercom, then such dream shows the tendency of yours to help others when its needed or when you are asked. The dream also indicates the perspicacious aspects of your personality. When you hear the voice because of the intercom, then it indicates the subliminal mind of yours and what it has to say to you. Perhaps the unconscious mind of yours suggests you to look deeper into some problem.
Read more about dreaming of Intercom in other dream meanings interpretations.