1. A time warp activation signal provider for providing a time warp activation signal on the basis of a representation of an audio signal, the time warp activation signal provider comprising: an energy compaction information provider configured to provide an energy compaction information describing a compaction of energy in a time warp transformed spectrum representation of the audio signal; and a comparator configured to compare the energy compaction information with a reference value, and to provide the time warp activation signal in dependence on a result of the comparison; wherein the energy compaction information provider is configured to provide a measure of spectral flatness describing the time warp transformed spectrum representation of the audio signal as the energy compaction information.