A distortion meter is used to detect frequencies that cause harmonic distortion. The meter allows for the user to alter or eliminate any source of distortion within the sound. This means that the user can visualize the frequency measurements made by the source sound and either add or completely eliminate any single wave within the sound's entire range of frequency.
Any sound is a direct result of a vibration of matter. Whether it’s a person sighing or an electric amplifier screaming when a guitar string is plucked, the sound contains frequencies that are used to create the volume and pitch of that sound. Within these naturally occurring frequencies, there might be a single frequency that causes an element of harmonic distortion, which in some cases is so minute that it isn’t readily detectable by human ear alone and in some cases can be immediately identifiable. The distortion meter can remove or change any one of these frequencies.
The most common uses for distortion meters relate to the music and sound production industry. Whenever sound is recorded in a controlled environment, and especially when the sound is recorded in a natural environment and mastered or engineered in a controlled environment, the entire array of sound waves must be analyzed and altered to be made easier on the eardrum. This means that any nuance of hiss, hum, reverberation or background noise that might cause frequencies inside the base sound must be considered. The distortion meter puts a visual on each different wave within the sound, making it possible for the user to alter or eliminate the specific wave that is responsible for the distortion.
Distortion also is present whenever there is an electrical current traveling through a circuit of any kind. This current causes vibration within the circuit, and the vibration causes distortion. The distortion within a circuit cannot be heard, so a distortion meter is used to eliminate all sources of distortion waves within the circuit when the current through the circuit needs to be maintained precisely.
The only way to achieve a pure and clean frequency within any sound or circuit is through the use of a distortion meter. The distortion meter can be used to set specific parameters at which the frequency or circuit might travel without creating the distortion, eliminating any sound waves or frequencies outside the parameters set by the user. Older distortion meters were analog machines that used input/output ports to complete the circuit needed to measure the sound. Newer models work digitally and might even be programs that can be installed on personal computers to measure the sound waves put into the program by the user.