Thursday, March 21st at 7.15 pm
David Griesinger, AES Silver Medal holder, will present the 40th Richard C. Heyser Memorial Lecture during the 146th Convention
This talk describes a few of the experiences I have had working with artists and musicians that taught me to hear what makes their art work. These experiences changed my life, and I hope that describing them will help others understand some of the amazing abilities of our ears and brains to detect, separate, and ultimately decode sonic information. Just as important, insight into these listening experiences can illuminate the possible physical processes by which the ear and brain achieve these feats. Such analysis often contradicts current dogma. For example, the phases of sounds higher than 1500Hz are often considered unimportant, but are actually critical to our ability to remember information. Working with these musicians and with acoustic enhancement taught me that many popular acoustic design goals can be counterproductive, and popular practices in sound reinforcement often reduce the ability to remember what was said. Accurate acoustic memory is short. Finding new models and methods for improving sound and acoustics requires reproducing live sound in a laboratory with high accuracy. We will describe an inexpensive technique that uses non-individual binaural recording and non-individual crosstalk cancellation for reproduction. The reproductions are startlingly real, and allow for instant comparisons between spaces. When used with measurement data the effects of individual reflections can be determined. Contrary to widespread practice early lateral reflections are often harmful, not helpful. We find that a reduction in the direct to reverberant ratio of only one dB, or the presence of a single reflection, can change sound from clear to muddy. These findings are being put into practice in old and new venues with exceptional results. We can reproduce live recordings made this way from all over the world. I will demonstrate this system to interested listeners during this conference as time and space allows.
David Griesinger is fascinated by the relationship between mathematical science and the recording, reproduction, and perception of music. He has given lectures and papers on recording, perception, and room acoustics around the world. His current work is on the mechanisms the ear and brain use to perceive sound, and how these mechanisms are affected by the acoustics in halls, operas, and classrooms of all types. After completing his PhD in physics in 1978 on the Mössbauer effect in Zinc 67, he independently developed one of the first digital reverberation devices, later to become the Lexicon 224. A more than thirty year stint as chief scientist for Lexicon followed, leading to many products, such as the LARES reverberation enhancement system and the Logic7 surround system. He has worked as a classical music recording engineer all his life, an avocation that encourages a certain skill in listening to sound. He has also been active as a singer in various music groups, including the Boston Camerata. He is the recipient of the gold medal of the German Tonmeister Society, a fellow and silver medal recipient of the Audio Engineering Society, and a papers reviewer for the AES, ASA, and Acta Acustica. He has been recently active as a music performance reviewer for www.classical-scene.com, taking special interest in the acoustical quality of venues. He lives in Cambridge Massachusetts, where enjoys his family, concerts, playing French horn, and making HD video recordings of musical performances. David is a Fellow of the AES and recipient of the Silver Medal.