Digital Audio Essentials: Sound, MIDI, and Formats

Understanding Sound Types

Analogue Sound Explained

Analogue sound imitates the vibrations of real sound. Its electrical signal has an analogue curve similar to a real sound wave.

Digital Sound Explained

Digital sound recording does not imitate vibrations but converts them into a binary code, the language computers use.

Digital sound is obtained through a converter. It transforms real sound (analogue) into a computer-readable format.

The Digitization Process

Role of the Converter

A converter is a device that transforms real sound into digital sound. The process is called sampling.

Sound Reproduction

To reproduce sound, the converter follows the inverse process, transforming the digital information back into real sound.

The MIDI System: Digital Communication for Music

What is MIDI?

Once music was digitized, many new digital devices became available on the market.

The MIDI system (Musical Instrument Digital Interface) was developed after an agreement between manufacturers to unite computer codes. MIDI is not a sound, a collection of sounds, or a sound file. It is simply a system for digital communication, hence the name 'MIDI protocol'.

MIDI is a connection protocol between digital devices (like synthesizers and computers) through which digital sound information can be sent to a computer.

MIDI Components

MIDI has two basic components:

• The interface is a device that sends and receives MIDI data from a computer.
• The cables and connectors connect devices and allow MIDI information to circulate between them.

MIDI Communication

MIDI data communication is done through a master device that acts as a controller. Its mission is to create MIDI messages and send them to one or various slave devices that receive and interpret the message.

Key Digital Audio Devices and Electronic Music

Essential Digital Instruments

The main digital devices that can connect with the MIDI system are:

• Sampler
• Drum Machine
• Sequencer
• Synthesizer

Sampler

The sampler digitally records samples of real sound.

Drum Machine

The drum machine allows rhythmic fragments to be programmed with percussion sounds.

Sequencer

The sequencer allows musical fragments sent from MIDI devices to be stored, programmed, and replayed.

Synthesizer

The synthesizer generates sounds from waves or noises created electronically.

Rise of Electronic Music

The sound produced by these devices started to be used in many different musical styles. They were the base for the development of electronic music.

Digital Audio Media and File Formats

Media and Formats Defined

Sound digitization sparked the development of new media and formats.

• Media is an element that stores digitally recorded data. This data is stored as sound files.
• A format is the way of coding the information.

Streaming Technology

Streaming is a type of digital information delivery that we use nowadays. It consists of accessing digital information on the internet without downloading the files.

Physical Digital Media

Examples of physical digital media include:

• CD (Compact Disc)
• DVD
• Super Audio CD (SACD)
• Digital Audio Tape (DAT)

Digital Audio File Formats

Uncompressed Formats (WAV, AIFF)

The typical uncompressed file formats are WAV and AIFF. Both are high-quality sound files that contain a large amount of information.

Compressed Formats (MP3)

The most common digitally compressed format is the MP3.