files may include but are not limited to the formats listed all of which pertain to one or more standard digital formats each file will typically contain in addition to compressed or non compressed content pertinent u201c meta information u201d including the format and rate at which the original analog signal was sampled in this embodiment that information resides in a file directory but other choices will be readily apparent to one of ordinary skill in the relevant art in light of this specification such as embedding the meta information in file headers in this embodiment a user requests that a specific file be played by choosing from a visual or audible menu presented at the user interface block 120 the user can also specify a u201c speed up u201d or u201c slow down u201d factor denoted here by u03b1 which determines the rate at which the file is played back if no u03b1 is specified it is taken to be equal to 1 so that the playback is at normal speed the controller 130 sends the file name to the storage control and buffer module 115 this module reads the file size format and sampling rate from the file directory and sends that information back to the controller 130 block 115 then starts to read as much of the requested file as its buffer capacity can accept the controller.