to a post filtering signal received from a decision module 1120 within the post filter 1100 the decision module performs one or more tests on the signal obtained from the decoder to arrive at a decision whether the post filtering module 1140 is to be active or inactive the decision may be taken along the lines of the functionality of the decision module 820 in fig8 which uses the original signal and or an intermediate decoded signal to predict the action of the post filter the decision of the decision module 1120 may also be based on similar information as the decision modules uses in those embodiments where an intermediate decoded signal is formed as one example the decision module 1120 may estimate a pitch frequency unless this is readily extractable from the bit stream signal and compute the energy content in the signal below the pitch frequency and between its harmonics if this energy content is significant it probably represents a relevant signal component rather than noise which motivates a decision to disable the post filtering module 1140 a 6 person listening test has been carried out during which music samples encoded and decoded according to the invention were compared with reference samples containing the same music coded while applying post filtering in the conventional fashion but maintaining all other parameters unchanged the results confirm a perceived quality improvement further embodiments of the present invention will become apparent to a person skilled in the art after reading the description above even though the present description and drawings disclose embodiments and examples the invention is not restricted to these specific examples numerous modifications and variations can be made without.