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January 1995: Volume 3, Number 5


Towards the Home Theater System of the Future: Measuring Audio- Visual Interactions

Presented by Professor Wieslaw Woszczyk, Ph.D., Chairman of Graduate Studies in Sound Recording at McGill University (Faculty of Music) in Montreal


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The Topic:

The growing consumer acceptance of a "home theater" concept has been clearly demonstrated by the recent commercial success of large video screens coupled with Dolby Surround and THX sound reproduction systems.

Taking the next step towards a more complete illusion of cinema (with an improved projection of sound and picture) requires a good understanding of the process by which the viewer integrates sound and picture into a total viewing experience.

Since last January, Professor Woszczyk has conducted work as Visiting Professor at Bang & Olufsen's Research and Development Department in Denmark measuring the dependence of the emotional involvement of viewers on the size of the television screen, and on the parameters of sound reproduction. A number of modifications have been implemented in the sound system, within the Dolby Surround standard, in order to enhance the total viewing experience. Preliminary results show that viewers clearly respond to changes in sound projection and to the balance of audio-visual stimuli.

The purpose of this presentation is to discuss procedures applied in experiments involving interactions between the modalities: hearing and seeing.

The quest speaker:

Dr. Wieslaw Woszczyk established the Graduate Program in Sound Recording at McGill University in Montreal, Canada, in 1979. He is currently a full-professor and the Chairman of Graduate Studies in Sound Recording at McGill.

Prior to joining McGill, Dr. Woszczyk was actively involved in the music recording industry in New York City, and continues as recording engineer and producer in addition to his consulting practice. His inventions find applications in products serving the audio industry, and as new techniques used in the recording practice.

Dr. Woszczyk has presented numerous papers at Audio Engineering Society Conventions, chaired sessions and conducted seminars. Recently, he was the chairman of the 9th AES International Conference Television Sound Today and Tomorrow in Detroit, and served as Audio Engineering Society Governor. He currently serves as chairman of the AES Membership Committee, and is Papers Co-Chair for the upcoming 99th AES Convention in New York in the Fall of 1995.

In 1991, Dr. Woszczyk received the Board of Governors Award from the AES. He is listed in the Marquis Who's Who in Science and Engineering. In 1994, Dr. Woszczyk spent his 6-months sabbatical in Denmark as a Visiting Professor at Bang & Olufsen A/S in Struer at the invitation of the Research and Development Department.

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AES Special Features


with Tom Shevlin

This one comes from Toronto's Dave Clark, a sound system design engineer for Engineering Harmonics when he is not mixing shows under the banner of his own firm, Live Audio.

I was at the house console for a rock band at Queen's University in the midst of a large crowd. One of the major numbers was coming up, which featured a long guitar solo. I put the fader up as the solo began, and the guitarist was up there wailing away, when I was called over by someone to the side of the console. We chatted briefly, but suddenly my attention was riveted... by the abrupt disappearance of the guitar from the mix.

A quick visual check of the console revealed nothing obviously wrong, so I pushed my way through the crowd to get to the stage. Soon the problem became apparent; first I saw the cable dangling from the end of the guitar amp mic stand with no mic attached, then I saw that the door leading off to the backstage had been opened.

I've lost mics at live gigs before... but never had anyone had so much nerve as to grab one at the very time when it should have been most easily noticed.

The author of this next story must remain anonymous.

One day I was called into Boss's ofice. Boss told me that "we" had a serious problem. Artist On The Comeback Trail had telephoned and complained about a problem with his most recent work. This problem he attributed to our mastering facility. As the resident Tech-Head, I was elected to identify and solve the problem as well as perform the requisite genuflection toward artistic ego.

Artist On The Comeback Trail and Record Company Guy arrived and I was summoned from my grotto to help solve the mystery. Artist On The Comeback Trail made his dislike of technical philistines clear by his manner. Record Company Guy was there to support Artist On The Comeback Trail and clearly sided with him.

We walked grimly into the mastering studio. I popped the master tape into the player and fired up the music. We basked in the glory of digital sound. This was still the early days of digital and these dvices were slowly but inoxerably making their way into the Biz. Artist On The Comeback Trail explained, in tones generally reserved for the village idiot, what the problem was. It seems he felt that some how "we" had screwed up when mastering his magnum opus and corrupted the dulcet tones of his masterpiece with some filthy high frequency tones.

We all listened as the music unspooled, Record Company Guy stared straight ahead, Artist On The Comeback Trail stared at me and I stared at the monitors. Sure enough I heard it. At a certain place in one of the tunes a subtle but unmistakeable high frequency whine appeared just under some vocals. I rewound the tape and tried again. Everyone agreed that yes, there it was.

Artist On The Comeback Trail and Record Company Guy both looked at me with a "What are you going to do about it?" stare. I tried to look as non-plussed as possible while my mind raced for inspiration. Was it leakage from an oscillator left plugged into the patch bay? Had it been coupled in from a nearby computer monitor? RFI? I mentally jumped from conclusion to conclusion. While all this was going on the music continued to play. . .

Slowly it dawned on me. This tone had a distinct pattern. It came and went as part of the song. I rewound the tape one more time and listened again. Sure enough, the tone appeared with the chorus every time. I pointed this out and rerolled the tape for both Artist On The Comeback Trail and Record Company Guy to hear. They heard. They agreed that yes the tone did come in with the chorus. They still wanted to know what I was going to do about it.

It was at this point that I asked Artist On The Comeback Trail an innocent question, "Did you sample part of this chorus and drop it in?". Artist On The Comeback Trail stared blankly as he digested the question. He then began to colour. His studio pallor began to redden starting at the neck and slowly rising to the forehead. He gave a very creditable imitation of a human thermometer.

I instantly knew four things. One: Artist On The Comeback Trail had sampled all or part of the chorus on the then primitive samplers. Two: Artist On The Comeback Trail had wound the sampler out to the maximum sample size and thusly allowed plenty of clock noise to be injected into the sample. Three: he knew this. Four: my hopes for a career in diplomacy had died a horrible death with the asking of that simple question.

Artist On The Comeback Trail never spoke another word to me as I rewound and removed the tape. Record Company Guy stared at me as if I had made a bad smell. We trudged in silence back to Boss's office. Artist On The Comeback Trail and Record Company Guy were seated in Boss's office with a great display of respect by Boss himself. Boss asked me for my opinion about the problem. I gave him my opinion. Boss looked at me silently for a moment and dismissed me back to my grotto.

Boss, Artist On The Comeback Trail and Record Company Guy conferred for some time. I was called away to work on some equipment and did not witness the departure of Artist On The Comeback Trail and Record Company Guy. I had some serious concerns about the state of my future employment for a few days after this meeting. Boss did not fire me: he did kind of look at me funny for a few days though.

This was the end of my career in customer relations. Boss never let me near the paying customers in this fashion again. I was henceforth relegated to the pits of technodom, never to be seen by the talent again.

The moral of the story is. . . Look before you peep.

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Logo Copyright 1995, Audio Engineering Society Toronto Section Bulletin

Articles may be used with the Author's Permission. Contact the Bulletin Editor: earlm@hookup.net

Editor: Earl McCluskie Assistant Editor: Anne Reynolds Layout Editor: Lee White

The Bulletin is prepared in print by Lee White, and on Horizons and the Internet by Earl McCluskie.