Pulse rate and envelope type still had highly significant effects [ F (1, 7) = 34.02, P = 0.0006, η 2 = 0.10; and F (5, 35) = 4.8, P = 0.0029, η 2 = 0.23 respectively), as did ITD type [ F (1, 7) = 174.2, P < 10 −5 , η 2 = 0.13).
In contrast, ENV ITD coefficients were much smaller, they failed to reach statistical significance in many individual cases, and they varied slightly less as a function of stimulus condition, from a minimum of 0.95 ms −1 for 900 pps stimuli with 50 ms wide envelopes at 5 bps, to a maximum of 2.403 ms −1 for 900 pps stimuli with 10 ms wide envelopes at 100 bps.
Note, however, that although ENV ITDs coefficients often failed to reach significance for any one animal in any one condition, only 4 of the 96 ENV ITDs coefficients shown in Fig. 4 were below zero.