Digital Audio

Digital Audio Report

Report on Digital Audio

Submitted to Avon Barksdale President of Bioware Technological Research Facility Maryland, Baltimore July 24th, 2007

By Matthew Angwin Head of the Black Mesa Research Facility Nevada, Mexico

Contents Executive Summary Introduction (1.0) ………………………………………….. Types of Players (2.0) ………………………………… …... Flash-Based Players (2.1) Hard-Drive Based Players (2.2) MP3 CD Players (2.3)

Recorders (3.0) …………………… …............................... Microphone (Mic) (3.1) Editing (3.2)

Production (4.0) …………………………………………... Delivery (5.0) ……………………………………………….. Optical Disk (5.1) Internet (5.2) Broadband (5.3) Flash Drives (5.4)

File Types (6.0) …………………………………………….. Other File Types (7.0) ……………………………………. Benefits (8.0) ………………………………………………. Future (9.0) ………………………………………………… References …………………………………………...........

Executive Summary New digital audio services like satellite radio, online radio, HD radio, and podcasting with new subscription and data service business models are changing the way consumers listen to radio. All four digital audio markets will grow steadily — by 2010, 20.1 million households will listen to satellite radio and 12.3 million households will synchronize podcasts to their MP3 players. Broadcasters and music labels must learn to deal with this new, fragmented audience. The keys to success will be subscriptions, ad targeting, and monetizing the many ways that digital audio will be consumed. (4)

Introduction (1.0) Digital audio uses digital signals for sound reproduction. This includes analogue-todigital conversion, digital-to-analogue conversion, storage, and transmission. Digital audio has emerged because of its usefulness in the recording, manipulation, massproduction and distribution of sound. Modern distribution of music across the internet through on-line stores depends on digital recording and digital compression algorithms. Distribution of audio as data files rather than as physical objects has significantly reduced costs of distribution. (1)

Tools (2.0)

Flash-based Players (2.1)

These are solid state devices that hold digital audio files on internal or external media, such as memory cards. Due to technological limitations, these are relatively low-storage devices, commercially ranging from 128MB to 8GB, such as the second generation iPod nano, the SanDisk Sansa series of players, and the iriver clix, which can often be extended with additional memory. As they are solid state and do not have moving parts, they are very resilient. (2)

Hard Drive-based Players (2.2)

Hard Drive-based Players or Digital Jukeboxes are devices that read digital audio files from a hard drive. These players have higher capacities, ranging from 1.5GB to 160GB, depending on the hard drive technology. At typical encoding rates, this means that thousands of songs — perhaps an entire music collection — can be stored on one player. Because of the storage capacity, devices that also display video and pictures are often hard-drive based. (2)

MP3 CD Players (2.3)

MP3 CD Player devices are that can play audio files from a CD-ROM in addition to audio CDs. It uses a lossy compression algorithm that is designed to greatly reduce the amount of data required to represent the audio recording, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. (2)

Recorders

(3.0)

Microphone (Mic) (3.1) The microphone is a device used for recording different types of audio.

Editing (3.2) In recent years, with the growing popularity of GNU/Linux, a number of Open Source software projects have sprung up in order to develop an open source audio editing program. This movement has been bolstered recently by the development of ALSA, and the Linux low latency kernel patch, which allow the GNU/Linux Operating System to achieve audio processing performance equal to that of commercial operating systems. The multi-platform package Audacity is currently the most fullyfeatured free software audio editor. (5)

Production (4.0)

- Podcasts - Studio Sound

Delivery (5.0)

Optical Disk (5.1)

In computing, sound reproduction, and video, an optical disc is a flat, circular, usually polycarbonate disc whereon data is stored in the form of pits (or bumps) within a flat surface, usually along a single spiral groove that covers the entire recorded surface of the disc. This data is generally accessed when a special material on the disc (often aluminium) is illuminated with a laser diode. The pits distort the reflected laser light. Most optical discs, with the exception of a few such as black CD-ROMs designed for the original Sony PlayStation, have a characteristic prismatic or iridescent appearance created by the grooves in the reflective layer. (1)

Internet (5.2) As the Internet’s community increases, more and more people are using it to transfer, record and edit their audio. At the present day, the internet is the most effective way to transfer audio.

Broadband (5.3) Broadband in telecommunications is a term which refers to a signalling method which includes or handles a relatively wide range of frequencies which may be divided into channels or frequency bins. The wider the bandwidth, greater is the information

carrying capacity. In radio, for example, a very narrow-band signal will carry Morse code; a broader band will carry speech; a still broader band is required to carry music without losing the high audio frequencies required for realistic sound reproduction.

Flash Memory (5.4)

Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed. It is a technology that is primarily used in memory cards, USB flash drives (thumb drives, handy drive, memory stick, flash stick, jump drive), which are used for general storage and transfer of data between computers and other digital products. Examples of applications include PDAs and laptop computers, digital audio players, digital cameras and mobile phones. (3)

File Types (6.0) There are a handful of audio file types you should be familiar with if you are planning to copy music off the Internet or even copy a CD. If you aren't sure what file types you are working with, you can distinguish any file type on your computer by the extension in the file name. The extension is the set of letters that follows the dot, as is in: seashore.wav. (1)

Waveform Audio (.wav) Waveform Audio (.wav) is a common file format. Created by Microsoft and IBM, WAV was one of the first audio file types developed for the PC. WAV files are defined as lossless, meaning that files are large and complete; nothing has been lost. Professionally recorded CDs are also a lossless audio source. (1)

MPEG-1 Audio Layer 3 (.mp3)

MPEG-1 Audio Layer 3 (.mp3) is a common, compressed WAV file. MPEG-1 files are about one-twelfth the size of WAV files. This is why MP3 players can accommodate hundreds of songs on a tiny chunk of storage space. (1)

Windows Media Audio (.wma) Windows Media Audio (.wma) was developed to compete with the MP3 format for Windows Media Player. Microsoft claims that the WMA files are compressed three times more than MP3s yet retain their original sound quality. (1)

Other Audio File Types (7.0)

Musical Instrument Digital Interface (.midi) Audio Interchange File (.aif, .aifc or .aiff.) Sun Audio (.au)

Benefits (8.0) As digital audio players have spread, new uses have been found for them. This includes podcasting, in which radio-like programs, or even TV-like video feeds, are automatically downloaded into the device to be played at the owner's convenience. As the years progress, it is becoming easier to effectively use digital audio to our advantage. (1)

Future (9.0) New digital audio services like satellite radio, online radio, HD radio, and podcasting with new subscription and data service business models are changing the way consumers listen to radio. All four digital audio markets will grow steadily — by 2010, 20.1 million households will listen to satellite radio and 12.3 million

households will synchronize podcasts to their MP3 players. Broadcasters and music labels must learn to deal with this new, fragmented audience. The keys to success will be subscriptions, ad targeting, and monetizing the many ways that digital audio will be consumed. (4)

References 1. http://en.wikipedia.org/wiki/Digital_audio 2. http://en.wikipedia.org/wiki/Digital_audio_player 3. http://en.wikipedia.org/wiki/Flash_drives 4. http://www.forrester.com/Research/Document/Excerpt/0,72 11,36428,00.html 5.

http://en.wikipedia.org/wiki/Audio_editing