A method, system and computer product for simultaneously activating at least two electrodes in a multichannel electrode array is presented. The method includes calculating pulse amplitudes of the electrodes in the multichannel array by taking into account parameters of spatial channel interaction reflecting geometric overlapping of electrical fields from each electrode. Calculating is based, at least in part, on place- independent impulse responses characterized by a first exponential decay constant a at a first side of the electrode and a second exponential decay constant ß at a second side of the electrode, such that the first exponential decay constant a is the same for each electrode in the array, and the second exponential decay constant ß is the same for each electrode in the array.
