1. Acoustics of Concert Halls and Rooms SOME BASICS OF ARCHITECTURAL ACOUSTICS Auditorium Acoustics Science of Sound, Chapter 23 Principles of Vibration and Sound, Chapter 11 Kimmel Center

2. Free field Reflections p vs r log p vs log r SOUND FIELD

3. Sound decay Sound decay in a 400 m 3 classroom Sound pressure level as a function of time for that room

4. GROWTH AND DECAY OF REVERBERANT SOUND RT = K (volume / area) RT = 0.161 V/A (V in m 3 ; A in m 2 ) If room dimensions are given in feet, the formula may be written: RT= 0.049 V/A (V in ft. 3 ; A in ft. 2 )

5. Decay of reverberant sound (a)and (b) are decay curves of sound pressure and sound level in a room with uniform energy distribution (c) shows different initial and final reverberation times (d) shows peaks due to prominent standing waves or room resonances

6. CALCULATING REVERBERATION TIME

8. Desirable reverberation times for various sizes and functions Variation of reverberation time with frequency in good halls

9. McDermott Concert Hall (Dallas)

10. Orchestra Hall (Chicago)

11. Meyerhof Symphony Hall (Baltimore)

12. Walt Disney Concert Hall

13. Disney

15. Kimmel Center Auditorium

16. BACKGROUND NOISE CRITERIA

17. Spatial impression Intimacy Early decay time Clarity “Warmth” Important criteria for concert halls:

18. Concert halls throughout the World