Index of content:
Volume 104, Issue 3, September 1998
- ARCHITECTURAL ACOUSTICS 
104(1998); http://dx.doi.org/10.1121/1.424359View Description Hide Description
This paper presents an extended diffuse field model for estimating the energy-time relationships in a room with an electroacoustic system. Discrete-time room impulse responses are used with a direct sound pulse and an exponentially weighted white-noise sequence modeling the reverberation tail. Transducer directivities and electronic finite impulse response (FIR) filters are included as model parameters. It is shown that the convolution of two exponentially weighted noise sequences is expressed as Early and total energy levels can easily be estimated and it is demonstrated that when direct sound components are omitted, this impulse response model results in the classical value of total energy supplied to a room by an electroacoustic system with feedback. Comparisons of such estimates with measurements in an auditorium with a single electroacoustic channel are presented. Four configurations were examined, including close and far microphone positions, combined with a single electronic delay or an FIR filter pattern. In the 500-Hz and 1-kHz octave bands, the early energy contribution from the electroacoustic channel spanned a 15-dB range. Predictions were reasonable, coming within 2 dB of the measured values for all four configurations.