As a way of collecting and playing music, the gramophone record and tape recorder have been supplanted by digital formats. The oldest is the standard CD. Players range from inexpensive personal units to expensive high fidelity players. When creating a digital archive of your own records, it is not necessary to use CDs; your decisions will be based on the equipment you have and your listening requirements. Compressed audio formats, such as MP3, AAC, and WMA, have become extremely popular. These formats use noise-shaping techniques to discard information in a way which cannot be perceived by most listeners, and there is a proliferation of devices on which to play such files.