Building Acoustics

100 Building acoustics d m . 2 E E η π = (3.122) Inserting Equation (3.121) into expressions for natural frequencies of an eleme ...

Waves in fluid and solid media 101 4 00 0 total internal 2 c 1 kk. k cc fm Sff ρ η ησ α π π = =+ + ⋅ ⋅ ∑ A (3.126) The element h ...

...

CHAPTER 4 Room acoustics 4.1 INTRODUCTION In talking about the concept of room acoustics we shall include all aspects of the beh ...

104 Building acoustics having walls of infinite stiffness. Solutions for such special cases may, however, give some general info ...

Room acoustics 105 4.2.1 Models for small and large rooms We have given an overview and some general remarks concerning the diff ...

106 Building acoustics combining the principles outlined above. A number of them have the possibility of simulating simple types ...

Room acoustics 107 Haas effect, the latter name in recognition of one of the many researchers on the phenomenon, Haas (1951). Ad ...

108 Building acoustics noise from the later part of the impulse response, thereafter compensating for the noise by assuming that ...

Room acoustics 109 in the first 50 or 80 milliseconds to the rest of the energy received. We have an early-to- late index Cte de ...

110 Building acoustics In addition to the parameters given above, there are others related to our binaural hearing, based on mea ...

Room acoustics 111 For the case of the one-dimensional standing wave, we named the points where the sound pressure was zero as n ...

112 Building acoustics 4.4.2 Sound pressure in a room using a monopole source We shall proceed by calculating the sound field in ...

Room acoustics 113 10 20 50 100 200 500 1000 Frequency (Hz) -50 -40 -30 -20 -10 0 p/(Q ω) dB Figure 4.3 Transfer function betwee ...

114 Building acoustics The result is shown by the dashed line in Figure 4.3. We see that there is a good fit between this result ...

Room acoustics 115 The unfiltered impulse response may now be filtered in either octave or one-third- octave bands to arrive at ...

116 Building acoustics 100 120 140 160 180 200 Frequency(Hz) 0 10 20 30 40 Relative sound p ressu re level (dB) Figure 4.6 Some ...

Room acoustics 117 of a resonance. The formula may be understood from the following facts: the resonance bandwidth is inversely ...

118 Building acoustics where V is the room volume and w is the energy density (J/m^3 ) in the room. We shall, for simplicity, in ...

Room acoustics 119 field in the sound is a superposition of plane waves. As seen from the formula, the intensity at the boundari ...