The noncorrelated sound-pressure level: A quantifiable metric for spatial characteristics in performance spaces
Christopher N. Blair · The Journal of the Acoustical Society of America · 1986
Recent research at MIT's Experimental Music Studio in binaural signal processing has led to a simple technique for separating the correlated portion of an audio signal received by a listener (the quasimonophonic portion related to the direct sound path, nondiffuse first-order ceiling reflections, etc.) from that portion of the signal in which the amplitude and/or phase relationships differ at each ear (due to lateral reflections of different path length, randomly arriving diffuse reflections, etc.). The noncorrelated sound-pressure level is easily measured by comparison of the relative voltage outputs of the microphones in the binaural head using a sound level meter. Real heads exhibit unsystematic amplitude and phase anomalies which render perfect cancellation of monophonic signals impossible. However, for the unequalized head used in this study, the noncorrelated sound-pressure level of monophonically presented pink noise is more than 10 dB below the sound-pressure level measured in octave bands by each ear separately. Future work and applications are discussed. [Work supported by MIT Provost Fund.]