Barcelona is today a multicultural city that hosts clearly different values, traditions, symbols and beliefs that shape the diverse cultural identities of its citizens. What is the influence of cultural diversity in the sounds of a city like this? The sounds of the cultures of Barcelona is a project that proposes working with sound as a means to better understand and preserve this cultural wealth of the city, from workshops in which participants seek and record those sounds to identify their own cultural identities and their neighborhood. The sound, then, is a tool that lets approach to this multiplicity of cultural identities of the city, while promotes the interest to creation and technology. The sounds obtained as a result of the workshops are included into an interactive web platform called idRadio and created by artist Xavier Bonfill, through which anyone can interact with those sounds and mix them to create different compositions online in real time. This project has the support of La obra Social La Caixa. A different experience and participatory to approach to different cultural realities and discover as sounds Barcelona.