A new Norwegian standard NS 8178 has been established with the aim to improve the facilities used for music; especially in relation to music teaching and rehearsing of non-professional ensembles it is found that the rooms are often very unsatisfactory in terms of the acoustics. The standard specifies recommended dimensions and reverberation times for various types of music and various sizes of music groups. Three types of music are considered; amplified music, powerful acoustic music, and weak acoustic music. The recommended reverberation times as a function of the room volume have been derived by considering the average strength G of the room and the typical sound power generated by musical instruments when played at forte. Thus for a given combination of musical instruments or singers, the expected sound pressure level in the room can be estimated. In a music room the sound pressure level at forte should neither be too loud nor too weak; in many cases an optimum range between 85 dB and 90 dB is recommended. For a certain ensemble, this leads to a recommended range of volume and reverberation time for an ensemble music room. For rehearsal rooms, a somewhat shorter reverberation time is recommended compared to performance rooms of the same size.

The standard also specifies the maximum and minimum reverberation time as a function of frequency in the range from 63 Hz to 4 kHz for different categories; amplified music (performance), amplified music (rehearsal), and acoustic music (both performance and rehearsal).