1. A data processing system which provides a user with vocalized information of web pages that are written in a markup language, comprising: call reception means for accepting a call from the user's telephone set; speech recognition means for recognizing a verbal message being received from the user's telephone set; web page data collection means, responsive to a request for a particular web page which is recognized by said speech recognition means, for making access to the requested web page to obtain web page data therefrom; keyword extraction means for extracting a predetermined keyword from the web page data; replacement means for locating a character string associated with the keyword extracted by said keyword extraction means, and modifying text of the web page data by replacing the located character string with another character string; and vocalizing means for vocalizing at least a part of the resultant text which has been modified by said replacement means.