LOUDNESS AND MASKING PATTERNS OF NARROW NOISE BANDS.

The loudness of narrow noise bands of equal intensity of 8. 5 kHz increases for bandwidths DELTA f greater than equivalent to 300 Hz. The masking pattern of a 10 Hz wide masker at 8. 5 kHz is inferior to the masking pattern of an equally intense 1800 Hz wide masker at 8. 5 kHz. The loudness differences are correlated to the different masking patterns of the narrow noise bands. Differences in the masking of test tones by narrow noise bands with different bandwidths at high center frequencies can be estimated, when weighting the envelope fluctuations of the masker by backward- and forward-masking functions.