Table 1.

Average RECD values by age

A. RA-1 coupler
	Frequency (Hz)
	250	500	750	1000	1500	2000	3000	4000	6000
0–12 months	5.4	9.8	10.0	13.0	14.4	14.5	18.5	21.6	22.4
13–24 months	7.3	10.2	9.9	12.6	13.7	14.2	16.1	18.5	15.5
25–48 months	4.0	8.5	8.7	11.8	13.2	13.2	15.5	16.2	15.4
49–60 months	2.8	8.0	8.5	9.8	11.9	12.7	14.0	15.0	14.8
> 60 months∗	2.2	4.6	4.3	6.3	7.7	8.8	11.2	13.1	13.7
B. RA-2 coupler
	Frequency (Hz)
	250	500	750	1000	1500	2000	3000	4000	6000
0–12 months	5.5	9.7	9.6	11.9	11.6	10.5	16.2	19.4	17.8
13–24 months	7.4	10.1	9.5	11.5	10.9	10.2	13.8	16.3	10.9
25–48 months	4.1	8.4	8.3	10.7	10.4	9.2	13.2	14.0	10.8
49–60 months	2.9	7.9	8.1	8.7	9.1	8.7	11.7	12.8	10.2
> 60 months	2.3	4.5	3.9	5.2	4.9	4.8	8.9	10.9	9.1