In recent years, hand-held types of data processing equipment, called PDAs (Personal Digital Assistants), have been utilized as equipment for sending electronic mail and faxes by sending data entered or stored by their data processing functions through wireless or radio communication means such as cellular phones. 
However, in order to achieve data communication through data processing equipment of the hand-held type, it is required to carry wireless communication means such as a cellular phone.  In addition, it is necessary to make a connection between the data processing equipment and the wireless communication means when communication is actually performed.  These requirements are very troublesome. 
Furthermore, the proper use of voice communication and data communication cannot be made smoothly. 
Accordingly, a wireless communication terminal has been developed in which a cellular phone and a hand-held data processing equipment are integrated with each other. 
Such integrated hand-held communication terminals can perform both voice communication and data communication.  However, since a voice entry microphone, data entry keys, and a touch panel are mounted on the same cabinet, when key entries or pen entries of data are made in the voice communication mode, various noises (input confirmation sounds, sounds produced by a pen contacting the touch panel, etc.)  due to entry operations are picked up by the microphone and mixed into telephone conversations, making it difficult to hold clearly audible conversations. 
In view of the disadvantages and deficiencies of the prior art devices described above, it is an object of the present invention to provide a communication terminal device which prevents noises due to data entry operations, such as pen-based entries, from being mixed in telephone conversations and hence permits clearly audible telephone conversations to be held.