Ripple density resolution of complex signals with additional rippled patterns

Two paradigms have been compared, which were aimed to investigate an effect of an additional signal pattern on ripple density thresholds. The discrimination between an extreme ripple density reference and rippled test pattern and the discrimination between a rippled reference and rippled test stimuli were measured. Stimuli contained or did not contain an additional signal pattern. The additional signal had the same length, bandwidth, and level as the signal. A ripple density of the additional signal was varied from 0 to 7 ripples/oct. For the stimuli with an additional rippled signal and non-rippled reference signal, the mean resolution was 11 ripples/oct with 16,47 ripples/oct for a non-rippled additional signal, and 52.4 ripples/oct with no additional signal. For a rippled additional signal, the mean resolution was 8.86 with the additional signal ripples/oct and 8.5 ripples/oct with no additional signal. For non-rippled reference signals results could be explained by the temporal mechanism when spectral pattern of the stimulus was unresolvable. For rippled reference signals, the data can be explained by similar cochlear excitation patterns.