Mitsumi electronic Noise Criterion Curves, PKA-A12HA4 PKA-A18HA4, NC-70, NC-60, NC-50, NC-40

5 NOISE CRITERION CURVES

PKA-A12HA4 PKA-A18HA4

NOTCH SPL(dB) LINE

High 43

Low 36

	90
	80
μbar)
dB (0dB=0.0002	70								NC-70
	60
LEVEL,									NC-60
PRESSURE	50
									NC-50
SOUND	40
									NC-40
BAND	30
OCTAVE
									NC-30
	20	APPROXIMATE
		THRESHOLD OF
		HEARING FOR							NC-20
		CONTINUOUS
		NOISE
	10	63	125	250	500	1000	2000	4000	8000

BAND CENTER FREQUENCIES, Hz

UNIT

WALL

3.3ft

3.3ft

MICROPHONE

8