Glossary definition of 'Real Time Analyzer'

(RTA) A device that displays the frequency content of an audio signal in real time. Originally this was achieved by filtering the signal into octave or fractional octave (often 1/3rd octave) bands and displaying the level in each band with a bar-graph LED meter. Now this is far more likely to be implemented in software and displayed on a computer screen.

Because the RTA divides the spectrum into equal fractional octave bands it will display a flat line with pink noise (pink noise having equal energy per octave) whereas an FFT spectrum analyzer (which divides the spectrum into bins of an equal number of Hz) will show a flat line with white noise which has equal energy per Hz.