An instrument that measures and provides a graphic representation of the magnitude of an electrical signal and its time variation. Since this signal may represent an acoustic event, the record, in units of DECIBELs versus time, shows the amplitude ENVELOPE of the sound. Also called graphic level recorder.
See COMPRESSION, DRONE, ENVELOPE and STATIONARY SOUND for examples of level recordings.
Compare: OSCILLOSCOPE, SONOGRAPHY, SOUND ANALYSER, SOUND LEVEL METER, SPECTROGRAPH, diagram under TEMPO, VU METER.