Psychoacoustic boundary conditions are to be better taken into account in the amplification of input signals of a hearing apparatus. To this end, a channel-specific compression characteristic curve is predetermined in a number of spectrally-separated processing channels of the hearing apparatus, which defines a relationship between an input level and an output level in the respective processing channel of the hearing apparatus. A respective input signal portion is amplified in each processing channel as a function of a channel-specific operating compression characteristic curve. A channel-specific input level threshold is predefined here for each processing channel. Finally, the respective channel-specific operating compression characteristic curve is then defined according to the predetermined channel-specific compression characteristic curve below the channel-specific input level threshold and the respective curve of the channel-specific operating compression characteristic curve is defined with a compression ratio of greater than 8 above the channel-specific input level threshold.