Figure 4.

d′ in vowel discrimination for individual subjects for sinusoidally amplitude modulated (SAM) noise maskers at two modulation depths (m) and for UN noise maskers from experiment 4. Level of the tone was the same for all subjects in an age group; masker condition order counterbalanced across subjects. Only infants were tested with 100% modulation depth SAM noise. Solid line represents mean d′ in UN noise masker and dashed line represents mean d′ in SAM noise masker by age group and modulation depth.