Resample

The act of recalculating samples in a sound file at a different rate than the file was

 

originally recorded. If a sample is resampled at a lower rate, sample points are removed

 

from the sound file, decreasing its size, but also decreasing its available frequency range.

 

Resampling to a higher sample rate, extra sample points are interpolated in the sound file.

 

This increases the size of the sound file, but does not increase the quality. When down-

 

sampling, one must be aware of aliasing.

 

 

Sample

The word sample is used in many different (and often confusing) ways when talking

 

about digital sound. Here are some of the different meanings:

 

A discrete point in time which a sound signal is divided into when digitizing. For example,

 

an audio CD-ROM contains 44,100 samples per second. Each sample is really only a

 

number that contains the amplitude value of a waveform measured over time.

 

A sound that has been recorded in a digital format; used by musicians who make short

 

recordings of musical instruments to be used for composition and performance of music

 

or sound effects. These recordings are called samples. In this manual, we try to use sound

 

file instead of sample whenever referring to a digital recording.

 

The act of recording sound digitally, i.e., to sample an instrument means to digitize and

 

store it.

 

 

Sample Rate

The sample rate (also referred to as the sampling rate or sampling frequency) is the

 

number of samples per second used to store a sound. High sample rates, such as

 

44,100 Hz provide higher fidelity than lower sample rates, such as 11,025 Hz. However,

 

more storage space is required when using higher sample rates.

 

 

Sample Size

Sample Value

See Bit Depth.

The sample value (also referred to as sample amplitude) is the number stored by a single sample. In 16-bit audio, these values range from -32768 to 32767. In 8-bit audio, they range from -128 to 127. The maximum allowed sample value is often referred to as 100% or 0 dB.

Secure Digital Music

The Secure Digital Music Initiative (SDMI) is a consortium of recording industry and

Initiative (SDMI)

technology companies organized to develop standards for the secure distribution of

 

digital music. The SDMI specification was created to answer consumer demand for

 

convenient accessibility to quality digital music, enable copyright protection for artists'

 

work, and enable technology and music companies to build successful businesses.

 

 

Shortcut Menu

A context-sensitive menu that appears when you right-click certain areas of the screen.

 

The functions available in the shortcut menu depend on the object being right-clicked as

 

well as the state of the program. As with any menu, you can choose an item from the

 

shortcut menu to perform an operation. Shortcut menus are used frequently for quick

 

access to many commands.

 

 

Signal-to-Noise Ratio

The signal-to-noise ratio (SNR) is a measurement of the difference between a recorded

 

signal and noise levels. A high SNR is always the goal.

 

The maximum signal-to-noise ratio of digital audio is determined by the number of bits

 

per sample. In 16-bit audio, the signal to noise ratio is 96 dB, while in 8-bit audio the ratio

 

is 48 dB. However, in practice this SNR is never achieved, especially when using low-end

 

electronics.

 

 

Society of Motion

SMPTE timecode is used to synchronize time between devices. The timecode is formatted

Picture and Television

as hours:minutes:second:frames, where frames are fractions of a second based on the

Engineers (SMPTE)

frame rate. Frame rates for SMPTE timecode are 24, 25, 29.97 and 30 frames per second.

 

 

Soft Synth

A soft synth is a software-based synthesizer. Downloadable Sounds (DLS) and Virtual

 

Studio Technology Instruments (VSTi) are two types of soft synths.

 

You add a soft synth control in the Mixing Console window for each software synthesizer

 

you want to use in a project.

 

 

Streaming

A method of data transfer in which a file is played while it is downloading. Streaming

 

technologies allow Internet users to receive data as a steady, continuous stream after a

 

brief buffering period. Without streaming, users must download files completely before

 

playback.

 

 

316 APPENDIX E