Table 2.

Levels of self-generated noise in octave-wide bands were compared for intervals before and after the interval identified by the listener as the signal interval. The mean difference (after-before) is reported below in dB for each age group and signal frequency. Larger numbers reflect higher noise levels after the interval identified by the listener as containing the signal.

	Frequency (Hz)
Age group	125	250	500	1000	2000	4000
4-6 yrs	3.2	4.2	4.1	3.1	2.5	1.7
7-10 yrs	3.8	4.1	3.8	3.0	1.7	0.7
11-16 yrs	5.5	5.9	4.8	3.3	1.4	0.4
adults	8.1	9.2	8.1	5.8	3.6	1.6