Auditory processing of amplitude modulation

ABSTRACT This paper gives an overview about recent experimental results and modelling efforts regarding the detection of amplitude modulations by human listeners. The Temporal Modulation Transfer Function (TMTF) indicates the relation between the just noticeable degree of modulation and the modulation rate. It is generally thought that the shape of the TMTF reflects an overall limitation of the auditory system to resolve fast fluctuations. A stimulus aspect to which we wifi pay some attention is the influence of the carrier type, which is usually either a broadband noise or a sinusoid. Specific differences in modulation detection for noise and for sinusoidal carriers indicate that TMTFs for these two carrier types might reveal different aspects of the auditory system and might not reflect the same process of temporal limitation. A multi-channel detection model including a modulation filterbank is described which does predict modulation detection data for random-noise carriers for many different conditions.