Global Music Resource

Effects processing can be done by either dedicated hardware device or with a stand-alone or plug-in software application. A single mono or stereo file, a mono or stereo track or a group of tracks simultaneously can have the effects, or a series of effects simultaneously, applied depending on the capability of the device, application and /or the processing power of the computer. Effects themselves are used to reshape the waveform of the original sound.

Once a WAV or AIFF sample is available in either RAM or from the hard drive, the digitized file can be opened and manipulated. Applying the effects to a track or series of tracks in real time, however, may result in a “destructive” edit where the original recording and spectral profile is changed permanently.

The sound can be processed many ways.

• Chorus
• Delay
• Envelope
• Filter
• Flanging
• Harmonizer
• Panning
• Phase (Phase Shift)
• Reverb (Reverberation)
• Reverse
• Time stretch
• Transposition
• Tremolo
• Vibrato

There is usually a graphical interface on the computer screen when one opens a file in an effects processing application that shows the reconstructed waveform based on the sampled values of the original analog waveform.

Chorus is obtained by layering a track or waveform with two or more identical tracks or waveforms that have had a slight time delay and modulation of the tracks (pitch shift), thus giving the effect of several instruments playing at once. The application of the effect is measured by the effect’s speed (rate) and alternation (depth). The effect is created with either a circuit oscillator or software oscillator.

Cross fading is the slow reduction of the gain of one track while a second track gain is faded in.

De-esser, as in the pronunciation of the letter “S”, is a limiter or compressor that will reduce the frequencies related to this letter that are produced when either spoken or sung.

Delay is the attempt to create an echo by adding a reproduction of the original signal at a constant rate of time after the original signal. The actual effect can be set from milliseconds to several seconds.

Distortion adds additional frequencies by clipping the waveform.

Echo is obtained by mixing a time-delayed signal output with the original version of the signal. The parameter adjustment also allows for the control of the signal repetition. It can be further adjusted by the volume decrease (or increase) of the repetition. The effect differs from Delay or Reverb by representing more distinct and wider reflections of the sound wave.

Envelope is the span of time through which the audio signal goes through various levels of Attack, Sustain and Decay.

Flanging is obtained by combining very slight, varying signals that have been time-delayed (by milliseconds) with the original audio signal to give a resonating effect. The application of the effect is measured by the effect’s speed (rate) and alternation (depth). The effect is created with either a circuit oscillator or software oscillator.

Gain is the increase in the (volume) level (measured in dB / decibels) of the audio signal.

Harmonization is the effect of detuning the delay and with the result being a two-pitch harmony.

Pan or Panning (Panorama) is establishing a balance of left and right output of the sample or establishing a higher degree of the signal or sound in one side of the stereo mix at the expense of the other side.

Phase (Phasing) is the combining an audio signal with a copy of that same signal but has had the relative phase reversed.

Pitch Shifting / Stretching is the changing (transposing) the root note of the waveform by semitone step to a new root note without changing the playback duration rate.

Reverb combines several Echo delay affects of the original signal in order to create the ambience and depth of how the actual sound would be diffused/reflected from surfaces within a certain type and size of confined structure or environment. The increase of the volume and intensity of the reverb simulates a particular environment.

Reverse is the reversal of the audio signal.

Ring Modulation a form of amplitude modulation, is one signal literally sent through another signal, however only the sum of the frequencies, and the difference between the two frequencies, both known as the Sideband frequencies, combined is now the new signal frequency output.

Time stretching is adjusting the length of time of which a waveform plays to fit a specified time frame. The idea is to change the length without changing the tone, vibrato, tremolo and other characteristics of the sound.

Tremolo is a rapid modulation of the volume level of the signal which is obtained by a modulating wave signal being applied to the amplitude of the carrier audio signal. The rate of the effect can also be adjusted.

Vibrato is a rapid modulation of the pitch of a note.

5.1 and 7.1 Editing / Panning

Mixing and editing is moving in the direction of mixing a finished product for Dolby Digital Surround Sound. This involves having hardware and software capable of separating out the 6 discrete channels and panning the signal to the correct speaker. First, 6 separate digital audio tracks must be created.