The aim of this thesis is to describe sound digitization and sound digitization projects in Croatia and United Kingdom. The thesis opens with defining sound as mechanical vibrations around us and gives a brief history of sound recording and sound carriers. Sound carriers can be analogue and digital. The types of carriers are categorized and analyzed. Suggestions about their usage and preservation is included. Next, the process of digitization is explained. Sound digitization is a complex process because new sound recordings have to be of good quality, and that depends on sampling, quantization, compression and filtering (e.g. the use of antialiasing filter). The process of digitization can be divided into phases and some of them are described in detail. Digitization of audio records has its goals and benefits. Finally, the thesis deals with digital cultural heritage. It plays an important role in the protection of old analogue audio records. As a part of saving cultural heritage in Croatia, project Croatian cultural heritage has been initiated. In United Kingdom, the British Library has initiated Archival Sound Recordings and few years later Save Our Sounds projects which are described in detail.