Digital Audio player

A digital audio player, or DAP, usually referred to as an MP3 player, is a consumer electronic device that has the primary function of storing, organizing and playing audio files. Some DAPs are also referred to as portable media players as they have image-viewing and/or video-playing support.

The immediate predecessor in the market place of the digital audio player was the portable CD player. Kane Kramer designed one of the earliest digital audio players which was capable of approximately 3.5 minutes of audio playback but it didn’t enter commercial production. The world’s first company to announce a portable MP3 player and the attendant system for uploading MP3 audio content to a personal computer and then downloading it onto a personal MP3 player was Audio Highway in1996.

The next company on the MP3 player scene was South Korea-based Saehan Information Systems which began selling its “MPMan” player in the middle of 1998. In 2001 the first MP3 players were installed into mobile phones in South Korea and the first artist to sell songs as MP3 file downloads directly to mobile phones was Ricky Martin. The innovation spread rapidly and by 2005, more than half of all music sold in South Korea was sold directly to mobile phones. The idea spread across the globe and by 2005 all five major handset makers, Nokia, Motorola, Samsung, LG and SonyEricsson had released musicphones. By 2006, more MP3 players were sold in musicphones than all stand-alone MP3 players put together. The rapid rise of the musicphone was a primary reason for developing iPhone. Today more than half of all mobile phones in the world have an MP3 player.

Digital sampling is used to convert an audio wave to a sequence of binary numbers that can be stored in a digital format, such as MP3. Common features of all MP3 players are a memory storage device, such as flash memory or a miniature hard disk drive, an embedded processor and an audio codec microchip to convert the compressed file into an analogue sound signal.

Most DAPs are powered by rechargeable batteries, some of which are not user-replaceable. They have a 3.5 mm stereo jack; music can be listened to with headphones, or played via an external amplifier. Nearly every DAP consists of some kind of display screen and a set of controls with which the user can browse through the library of music contained in the device, select a track, and play it back. The controls can range from the simple buttons as are found on most typical CD players for skipping through tracks or stopping/starting playback to full touch-screen controls. One of the more common methods of control is some type of the scroll wheel with associated buttons.

Content is placed on DAPs typically through a process called “syncing”, by connecting the device to a personal computer, typically via USB, and running any special software that is often provided with the DAP on an enclosed CD-ROM, or downloaded from the manufacturer’s website. The music, or other content such as TV episodes or movies, is added to the software to create a “library”. The library is then “synced” to the DAP via the software. Many players have a built-in microphone which allows recording. Usually recording quality is poor, suitable for speech but not music.

The risk of hearing damage from digital audio players depends on both sound level and listening time. The listening habits of most users are unlikely to cause hearing loss, but some people are putting their hearing at risk, because they set the volume control very high or listen to music at high levels for many hours per day. Such listening habits may result in temporary or permanent hearing loss, tinnitus, and difficulties understanding speech in noisy environments.