Is it possible to have high energy compaction in audio signal?
Depends on what you mean exactly by "energy compaction". 

Most audio signals are "pink" in nature, so doing any type of frequency transformation will "compact" the energy towards the lower frequencies and most audio codecs use this property. Not sure you get "high" energy compaction: a typical FLAC compression rates are about 30% size reduction or so.

It's more difficult to compact a signal in time through some sort of linear transformation or invertible transformation. This would really depend on what exactly you are trying to do and what the general properties of your signal are.