Across-channel masking is modeled either by energy subtraction or by suppressing adjacent modulation frequencies.

Evidence

To simulate across-channel (AC) processes, two different versions of the monaural part of the model were used. The first version is based on the approach of Piechowiak et al. ( 2007 ). In this approach a weighted sum of modulation filters at the output of off-frequency auditory filters was subtracted from the corresponding modulation filters at the output of the on-frequency filter. In contrast to Piechowiak et al. ( 2007 ), a multi-auditory-channel version of this approach was used. Since the weighting is essentially based on the energy in the auditory filters it will be referred to as the energy-based AC model in the following. The second version of across-channel processing is based on the assumption that modulation in off-frequency auditory filters channels hampers the processing of the modulation filters tuned to the corresponding modulation frequency in the on-frequency auditory channel. This detrimental effect is realised by assuming that modulation frequencies adjacent to the modulation created by the masker-interferer distance could not be processed. This was implemented in an extreme form by setting the output of the modulation filters tuned to frequencies adjacent to the interferer-masker distance induced modulation frequency to zero. This approach is referred to as the modulation-based AC model. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3478

Categorization

• DEFINE: Distinguishes two rival modeling mechanisms for across-channel processing: energy-based subtraction versus modulation-frequency suppression.