The paper defines the concept of radio media and shows the development of its market in the Republic of Croatia. It defines the concept of the media audience, focused on radio listeners. Subsequently, the results of the agency research of the use of media, in particular radio, will be presented. The special chapter outlines the data on Croatian local radio stations Extra FM and Enter Zagreb, as well as a comparison of their programs. The aim of the research part of the work was to find out if the audience of said radio stations differed according to gender, age, qualification and monthly income and what are their listening habits. The survey was filled by 50 listeners of Enter Zagreb and 50 listeners of Extra FM, and the survey was conducted in February 2019. The results have demonstrated that the format of Enter Zagreb is attracting more male listeners of higher or high education level and higher monthly income. On the other hand, Extra FM is mostly attracting a female audience of a high school education and lower monthly income. Despite the fact that the audiences of both Croatian radio stations are demographically different, when we took a closer look at their listening habits, we confirmed that radio content is mostly used as a background noise while doing some other activity, especially during the use of new media. The data we analyzed is a good foundation for future qualitative research of greater and more relevant sample audiences which will help provide a more detailed view into the structures of audiences of radio stations and their habits of listening. This will help in recognizing the type of audience that a specific radio format attracts and how to best adapt the radio programming to them, as well as the communication development of radio as a media with new media.