The invention relates to a method and an apparatus for processing an audio signal, wherein the method comprises the steps of: filtering an audio signal into at least two frequency band signals, generating for each frequency band signal a plurality of sub-band signals, wherein for at least one frequency band signal the plurality of sub-band signals are generated using a time to frequency domain transform and for the at least one other frequency band the plurality of sub-band signals for the other frequency band are generated using a sub-band filterbank, and the apparatus comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to perform the method.