Abstract:

Paul's favorite ``in-house'' project in the 1960's was his auditorium synthesis system. He devised an electro-acoustic laboratory listening environment which simply divided a test sound field, excited by an anechoic recording, into the three basic components called ``direct,'' ``envelopment,'' and ``reverberance.'' The envelopment factor was the summation of early delayed reflections which surrounded the listener at the sides via loudspeakers. Paul was primarily looking for how much envelopment, or lateral early energy, a listener preferred relative to the direct sound level. At around the same time, he was using a nitrogen jet ultrasonic noise source to model test exactly how much lateral early energy was possible. He found that in a conventional hall with the best possible lateral energy design, the amount of envelopmental energy available at most seats was around 3 to 5 dB lower than ``desired.'' Concurrently, Marshall and then Barron extended the previous work of Keet and Kuhl in developing the parameter called ``lateral energy fraction,'' which essentially quantified Veneklasen's envelopmental energy. Computer systems later allowed the actual measurement of typical lateral energy values in concert halls. Veneklasen's findings will be compared to the actual measured values for hall's of well-known quality.