Modulation thresholds for sinusoidally amplitude-modulated (SAM) broadband noise were obtained as a function of modulation frequency from normal-hearing subjects and from subjects with primarily high-frequency hearing losses. The resulting Temporal Modulation Transfer Functions (TMTFs) indicated that the impaired subjects were generally less sensitive to modulation. In addition, unlike previously published data for normal-hearing subjects, a level effect was observed in the impaired subjects: sensitivity decreased, particularly at high modulation frequencies, as noise level decreased. TMTFs were also obtained from normal-hearing subjects for SAM noise that was lowpass filtered at 1.6 kHz after modulation, and presented with a continuous, 1.6-kHz highpass masker. These TMTFs were similar to the broadband TMTFs in the impaired subjects; this suggests that the impaired temporal processing in the hearing-impaired subjects is a result of a narrower effective bandwidth. [Supported by NIH NS 12125.]