Audio players and specifically, portable audio players, have developed dramatically since their innovations. Music players of widely varying type have evolved through various forms over the years, from portable single transistor radios to tape cassette players to compact disc players and more recently to MP3 players, which enable a user to download audio material from an internet site and store same in storage medium of a player in an MP3 format for subsequent selective listening. Audio and video files, before being compressed, typically consist of 16 bit samples recorded at a sampling rate more than twice the actual audio bandwidth, which yields more than 1.4 Mbit to represent just one second of stereo music in CD quality. Since such vast amounts of data are unwieldy, data compression is required. Audio and video information may be compressed to remove redundancy within the information and allows the information to be stored using less memory. Digital audio is a basic component of any video or multimedia application. Due to the large bandwidth occupied by digital audio in any such application, compression of the audio data is an important part of the encoding process. Audio compression is generally performed by taking into consideration the characteristics of the audio signal and the human perception system as embodied in a psychoacoustic model. There are two main high-fidelity audio compression techniques: the Motion Picture Expert Group (MPEG) audio standard and the Dolby Digital audio compression algorithms developed by the Dolby Laboratories. MPEG (Motion Picture Experts Group) provides standards for compressing digital audio and video signals. In order to accommodate different levels of audio quality with the compression method, MPEG is further divided into Layer1, Layer2 and Layer3. Generally speaking, the higher the level of the layer, the more complicated the compression method, the distortion of the corresponding recovered audio signal is much less, and the effect is better. MP3 (MPEG Layer 3) is the MPEG layer 3 audio standard. Using MPEG audio coding, the original sound data can be reduced by a factor of 12, without sacrificing sound quality. MP3 utilizes the inverse-modified discrete cosine transform (IMDCT) and the sub-band coding techniques, whereby MP3 can achieve such high compression rate. The MPEG layer3 compression standard, using the MPEG layer3 (MP3) compression algorithm, is widely used in the application of digital broadcast and multimedia.

Developments in processing and storage technology have greatly expanded the ability of individuals to use microprocessor based devices for the recording and playback of sounds and images. Digital electronic products, such as digital camera, MP3 player, cellular phone, etc., are required with larger capacity of storage media to satisfy the demand of digital images and music with higher qualities by the users. The storage devices for audio data and audio players in the market include magnetic tapes and magnetic recorders, a compact disk (CD) and a CD-ROM, a digital versatile disk (DVD) and a DVD ROM, and flash memory storage. Magnetic recorded tapes are not able to be sustained for a long time, and are easy to be demagnetized by ultra-violet ray, plus their small capacities and being sensitive to noise signals which make the magnetic recorded tapes gradually decline on the market. The flash memory cards have the advantages of small size, large capacities, accessing quickly, and easy to install and carry. The use of non-volatile memory systems such as flash memory storage systems is increasing due to the compact physical size of such memory systems, and the ability for non-volatile memory to be repetitively reprogrammed. A major advantage of flash over ROM is that the memory contents of flash may be changed after the device is manufactured. The ability to repetitively reprogram non-volatile memory included in flash memory storage systems enables flash memory storage systems to be used and reused. Flash memory has found wide acceptance in many types of computers, including desktop computers, mobile phones and hand held computers. Flash memory is also widely used in digital cameras and portable digital music players. The flash memory is divided into a NAND-type flash memory having a large memory capacity and a NOR-type flash memory having a high processing speed. The NAND-type flash memory which attains high integration and has a replaceable hand disk is mostly used to store high integration voices or images. Flash memory storage systems may include flash memory cards and flash memory chip sets. Flash memory chip sets generally include flash memory components and a controller component. A flash memory chip set may be arranged to be assembled into an embedded system. In the case of an MP3 player, a number of digitized audio files in the form of MP3 files are stored in a storage medium included in or coupled to the player in a fashion deemed most suitable to that user.

An MP3 player manages digital contents in a memory in the form of a file and has a central processing unit (CPU) for controlling internal operations. Typically, an MP3 player will store various audio items internally on a storage disk. When the user makes a selection to play one of the stored audio items, the audio item must first be loaded into semiconductor memory before the audio item begins to be played. Once an MP3 player finishes playing a song, the MP3 player begins searching for and loading the next song. MP3 players also are generally only capable of keeping track of and playing one song at a time. An MP3 player retrieves compressed audio data from the disk and stores it in an internal memory buffer. In the MP3 player, a WAV file obtained by digitally sampling an audio signal from the performance of a musical piece and/or the singing of a song is encoded in the MP3 format, and the resulting file compressed in the MP3 format is stored in a flash memory. In the case of MP3 files, a user can select and digitally encode any number of music selections each of which could have been mastered at different volume levels. MP3 files can be downloaded from the Internet using a computer and special software. Generally, MP3 player has communication functions for downloading a file through a serial or parallel cable to a computer. A personal computer programmed with the appropriate software can covert digital music from a CD (compact disk) into MP3 format. Portable MP3 players rely on batteries for their portability and are typically provided with a headset for user listening. Portable MP3 players are capable of storing about 10-30 music selections. With an add-in memory card, such devices can carry a total of about twenty (20) music selections. These MP3 players that store the MP3 compressed digital audio recordings in an electronic solid state memory consume comparatively little electrical power. Thus, such MP3 players provide an extended playing interval without battery replacement or recharging for the limited number of selections which they can store.