The intrinsic electrical noise or hiss produced by a microphone, measured in the absence of any input signal. Usually the self-noise specification is A-weighted: a self-noise figurespec of 18dB SPL or less is excellent, 28dB SPL is good, and over 35dB SPL is not good enough for quality recording. Dynamic mics have very low self-noise. The S/N ratio of a microphone is the difference in dB between the microphone’s sensitivity and its self-noise. See also reach.