Until the FCC removed the ban on connecting non-AT&T equipment to the phone lines, few people would have thought of the telephone as a consumer electronic item. Now, however, there can be little doubt that it is one. Not only did this decision unchain the creative genius of free enterprise, but it coincided in time with the emerging availability of inexpensive MSI and LSI chips. The result has been a proliferation of phones and features undreamed of just twenty years ago. The Bell System's development of Touch-Tone® dialing led to the development of the DTMF (dual-tone, multi-frequency) encoder and, later, decoder chips. Sharply declining prices on digital memory chips led to their incorporation in many phones for phone number storage and rapid dialing. Phones with memory may be broken down into three groups:

Anyone who has ever listened to a phone conversation where the speaker tried to make a comment while covering the receiver with his hand knows that this does a very poor job of masking the sound. It is therefore surprising that a concept as simple as the privacy or mute switch did not come into wide use until the lines were made available to all equipment that met phone company specifications.

Speakerphones have existed for some time, but they tended to be prone to acoustic feedback. Current versions, however, electronically sense where the input is coming from and open the channel only in the direction it needs to go. When the speaker changes, signal flow in the opposite direction is enabled.

Cordless phones have benefited from inexpensive transmitter and receiver ICs and have declined in price to where they are now a popular option. They are almost too popular, in fact. In some wealthy neighborhoods, there have been so many cordless phones that two related problems have become evident. The first is interference between phones, and the second is eavesdropping.