ROOM ACOUSTICS DEFINITION: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION DEFINITION: THE BEHAVIOR OF SOUND IN ENCLOSED SPACES. HOW THE ACOUSTICAL ENVIRONMENT AFFECTS THE FUNCTIONS & ACTIVITIES IN THE SPACE. INTRODUCTION

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION SOUND DISTRIBUTION: ROOM SHAPE PLACEMENT OF REFLECTIVE AND ABSORPTIVE SURFACES. INTRODUCTION

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION SOUND ABSORPTION

ABSORPTION COEFFICIENT ROOM ACOUSTICS ABSORPTION COEFFICIENT: DESCRIBES THE FRACTION OF THE INCIDENT SOUND ENERGY THAT A MATERIAL ABSORBS. THEORETICALLY IT CAN VARY FROM 0 (NO SOUND ENERGY ABSORBED) TO 1.0 (PERFECT ABSORPTION OF ALL INCIDENT SOUND ENERGY) INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION ABSORPTION COEFFICIENT

NOISE REDUCTION COEFFICIENT ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION NOISE REDUCTION COEFFICIENT

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION SABINES

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION DIRECT SOUND

ROOM ACOUSTICS IMPROVING THE DIRECT SOUND PATH: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION IMPROVING THE DIRECT SOUND PATH: PLACING THE AUDIENCE AS CLOSE AS POSSIBLE TO THE STAGE. DIRECT SOUND

PLACING THE AUDIENCE AS CLOSE AS POSSIBLE TO THE STAGE. ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION PLACING THE AUDIENCE AS CLOSE AS POSSIBLE TO THE STAGE.

PLACING THE AUDIENCE AS CLOSE AS POSSIBLE TO THE STAGE. ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION IMPROVING THE DIRECT SOUND PATH: PLACING THE AUDIENCE AS CLOSE AS POSSIBLE TO THE STAGE THROUGH STACKED BALCONIES. PLACING THE AUDIENCE AS CLOSE AS POSSIBLE TO THE STAGE.

IMPROVING THE DIRECT SOUND PATH ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION IMPROVING THE DIRECT SOUND PATH: RAISING THE SOURCE IN HEIGHT. IMPROVING THE DIRECT SOUND PATH

IMPROVING THE DIRECT SOUND PATH ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION IMPROVING THE DIRECT SOUND PATH: RAISING THE SOURCE IN HEIGHT. IMPROVING THE DIRECT SOUND PATH

IMPROVING THE DIRECT SOUND PATH ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION IMPROVING THE DIRECT SOUND PATH: RAKING THE SEATING. IMPROVING THE DIRECT SOUND PATH

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION REFLECTED SOUND PATH

ROOM ACOUSTICS RAY DIAGRAMS: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION RAY DIAGRAMS: PROCEDURE FOR ANALYZING REFLECTED SOUND. RAYS ARE DRAWN NORMAL TO THE SPHERICALLY PROPAGATING OF WAVES. SPECULAR REFLECTION IS ASSUMED. RAY-DIAGRAMS

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION RAY-DIAGRAMS

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION LIMITATIONS OF RAY DIAGRAMS: THE SPACE IS THREE-DIMENSIONAL BUT THE DIAGRAM IS TWO-DIMENSIONAL. COMPLICATED BY VARIOUS SPEAKING POSITIONS. NOT APPLICABLE TO LOW-FREQUENCIES (BELOW 250HZ). RAY-DIAGRAMS

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION DIFFUSION OF SOUND: WHEN SOUND REFLECTS OFF A FLAT HORIZONTAL SURFACE, A DEGREE OF DIFFUSION IS PROVIDED.

ROOM ACOUSTICS FLUTTER ECHO: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION FLUTTER ECHO: REPEATED ECHOES TRAVERSING BACK AND FORTH BETWEEN TWO PARALLEL SURFACES. REQUIRES AN IMPULSE SOURCE. PERCEIVED AS A BUZZING OR CLICKING SOUND. FLUTTER ECHO

STANDING WAVES (ROOM RESONANCE) ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION STANDING WAVES (ROOM RESONANCE): SIMILAR TO FLUTTER IN PRINCIPLE BUT CAUSED BY PURE TONE SOURCES. PERCEIVED AS VARIATIONS IN SOUND LEVEL. STANDING WAVES (ROOM RESONANCE)

STANDING WAVES (ROOM RESONANCE) ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION DESCRIPTION: STANDING WAVES WILL OCCUR WHEN PARALLEL WALLS ARE SOME INTEGRAL MULTIPLE OF HALF A WAVE LENGTH APART. THEY OCCUR ONLY IN SMALL ROOMS (30’ OR LESS FOR MUSIC & 15’ OR LESS FOR SPEECH. STANDING WAVES (ROOM RESONANCE)

FLUTTER ECHO & ROOM RESONANCE ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION METHODS OF CONTROL: SOUND ABSORBING TREATMENT. NONPARALLEL-WALL SURFACES. SOUND-DIFFUSING WALL MODULATION. FLUTTER ECHO & ROOM RESONANCE

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION METHODS OF CONTROL: NONPARALLEL-WALL SURFACES & SOUND-DIFFUSING WALL MODULATION.

INCLINED FLAT SURFACES ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION GREATER DIFFUSION IS PROVIDED. IF THE INCLINATION IS UP TOWARD THE AUDIENCE, SOUND IS PROJECTED DEEPER INTO THE ROOM. CAN INCREASE USEFUL CEILING REFLECTIVE SURFACE. INCLINED FLAT SURFACES

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION GREATER DIFFUSION IS PROVIDED. IF THE INCLINATION IS UP TOWARD THE AUDIENCE, SOUND IS PROJECTED DEEPER INTO THE ROOM. CAN INCREASE USEFUL CEILING REFLECTIVE SURFACE. SOUNDING BOARD

ROOM ACOUSTICS DESCRIPTION: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION DESCRIPTION: THE SOUND SOURCE SHOULD BE CLOSELY AND ABUNDANTLY SURROUNDED WITH LARGE SOUND-REFLECTING SURFACES, SUCH AS PLASTER OR CONCRETE, TO INSURE ADEQUATE LOUDNESS IN REMOTE AREAS. SOUNDING BOARD

PROVIDES THE GREATEST DIFFUSION. ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION PROVIDES THE GREATEST DIFFUSION. IN A DIFFUSE SOUND FIELD THE SOUND LEVEL REMAINS RELATIVELY CONSTANT THROUGHOUT THE SPACE WHICH IS EXTREMELY DESIRABLE FOR MUSIC.

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION CONVEX SURFACES

ROOM ACOUSTICS CONCAVE SURFACES: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION CONCAVE SURFACES: REFLECTED SOUND IS CONCENTRATED INTO CERTAIN AREAS. CREATES HOT AND DEAD SPOTS ACOUSTICALLY. FOCUSING

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION FOCUSING

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION REFLECTION OF SOUND ALONG A CURVED SURFACE FROM A SOURCE NEAR THE SURFACE. ALTHOUGH THE SOUND CAN BE HEARD AT POINTS ALONG THE SURFACE, IT IS INAUDIBLE AWAY FROM THE SURFACE.. CREEP

ROOM ACOUSTICS METHODS OF CONTROL: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION METHODS OF CONTROL: SURFACE UNDULATIONS. SOUND ABSORBING TREATMENT. CREEP

EERO SAARINEN, MIT CHAPEL ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION EERO SAARINEN, MIT CHAPEL

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION ECHO: THE DISTINCT REPETITION OF THE ORIGINAL SOUND SUCH THAT IT IS SUFFICIENTLY LOUD TO BE CLEARLY HEARD ABOVE GENERAL REVEBERATION. ECHOES

ROOM ACOUSTICS DESCRIPTION: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION DESCRIPTION: ECHOES OCCUR WHEN THE REFLECTED SOUND PATH EXCEEDS THE DIRECT SOUND PATH BY MORE THAN 60 FEET. ECHOES

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION CONTROL: USE OF SOUND ABSORBING MATERIAL OR INCLINING CEILING SURFACE. ECHOES

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH DESCRIPTION RAY-DIAGRAMS HORIZONTAL SURFACES INCLINED SURFACES CONVEX SURFACES CONCAVE SURFACES ECHOES DIFFRACTION REVERBERATION THE BENDING OR FLOWING OF A SOUND WAVE AROUND AN OBJECT OR THROUGH AN OPENING. IMPINGING SOUND WAVES WILL READILY DIFFRACT AROUND PANELS THAT ARE SMALLER THAN THEIR WAVELENGTH. DIFFRACTION

ROOM ACOUSTICS REVERBERATION: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION DESCRIPTION PATTERNS OF REVERBERANT DECAY REVERBERATION TIME REVERBERATION: THE PERSISTENCE OF SOUND AT MID-FREQUENCIES. DETERMINED BY ROOM VOLUME AND TOTAL ABSORPTION AT THAT FREQUENCY. REVERBERATION

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION DESCRIPTION PATTERNS OF REVERBERANT DECAY REVERBERATION TIME SOUND IN A LARGE ROOM

ROOM ACOUSTICS INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION DESCRIPTION PATTERNS OF REVERBERANT DECAY REVERBERATION TIME SOUND IN A SMALL ROOM

ROOM ACOUSTICS REVERBERATION TIME: INTRODUCTION SOUND ABSORPTION DIRECT SOUND PATH REFLECTED SOUND PATH REVERBERATION DESCRIPTION PATTERNS OF REVERBERANT DECAY REVERBERATION TIME REVERBERATION TIME: THE TIME REQUIRED FOR SOUND TO DECAY 60 DECIBELS AFTER THE SOURCE HAS STOPPED. REVERBERATION TIME