Rehearsal Rooms for Acoustical Instruments - Comparing Measurements and Subjective Experiences
Examensarbete för masterexamen
Sound and vibration (MPSOV), MSc
The room acoustic conditions in rehearsal rooms are important for the musician’s rehearsal experience. The Norwegian Standard NS 8178:2014 specifies differentiated criteria for rooms used for music rehearsal and performance. The criteria that are relevant for the room acoustics in rehearsal room for solo instrumentalists are specifications on room size and geometry, acoustic treatment, and reverberation time. There has been limited research on rehearsal room acoustics, and this thesis investigates the connection between subjective experience of a rehearsal room and the measurable characteristics. This thesis deals with objective and subjective descriptions of six music rehearsal rooms intended for solo musicians playing an acoustical instrument, investigating the connection between the two. The objective characteristics of the rehearsal rooms are gained by four different means: Three kinds of measurements and a room acoustical simulation. The measurements are traditional impulse response measurements that yield common room acoustic parameters, stage parameter measurements in a defined playing position and reflection measurements to gain the frequency characteristics of the wall surfaces of the rooms. The impulse response measurements are used for calculating room acoustical parameters, as well as being studied in waterfall plots for visual examination. The simulations yield the reflectogram of the defined playing position of each rehearsal room. Subjective experiments are performed by introducing musicians one at a time to the rehearsal rooms, asking them to play in the room’s defined playing position, after which they answer a questionnaire about the room acoustical conditions. Comparisons between the objective and subjective results indicate that rooms where the impulse response has highly irregular amplitudes both over time and frequency during the first time interval are disadvantageous for the experience of the rehearsal room. Further, the results show that there is a subjective difference of the suitability for rehearsal between rooms despite the fact that they meet the criteria of the standard. The comparisons indicate that the values of the di˙erent parameters should be uniform over frequency. Short reverberation time, especially EDT, seem favourable. As do high clarity, either in the form of C80 or TS. Finally, the investigations show that simple measurement techniques may explain why some rooms are experienced to have sharp and metallic sound.
Building Futures , Akustik , Building Futures , Acoustics