Training for Non-Technical Cinema Employees

Audio (Sound Basics): Part 1

Sound is all around us. We don’t need any particular talent to use it. Doctors tell us that we can hear sounds in the womb.

Using sound well is a different story. Being able to judge sound, to know if it is the best possible for your clients – or at least acceptable – is another different story.

For a simple definition, “Sound” is what we hear. But actually every sound involves hundreds of steps. These steps begin with a motion that takes place at one point. The drummer hits the drum, and it vibrates, the bell gets hit and it vibrates, we push air up our throats and make it vibrate.

We can’t see it, but you can visualize it by thinking about it like a pebble that is thrown into a pond.

Very quickly, that one motion starts a series of motions that spread out as waves. Like the circular wave on the water, sound is a wave that spreads out from the source.

There are some differences with the water comparison though. The first is that we see the pond surface as a flat surface. Our sound wave is different – it goes out in all directions from a speaker. It is similar to the way that a light goes out from a flame – from the top and bottom and all sides at once, every angle to every corner. The second difference is that the spreading wave, that energy spreading out from the speaker, is pushing on air. Air acts differently than water.

But the main thing is true – a wave of sound and a wave on water and a wave of light all carry energy.

Eventually the energy of the wave reaches our ears. It then goes inside the ears and finally (through a process that is so sophisticated that it seems like it must be magic), the wave motion turns into electricity. That energy goes down some nerves.  That new energy wave of electricity transmits what we heard, that original motion, to the brain for analysis.

Sometimes the word Sound and the word “Audio” seem like they mean the same thing. But they can be different. We will say that “audio” is a type of sound that is being played through some equipment. This is the sound that we hear in the movie auditorium.

Grammar in English is complicated though, so it is not always true. We will say that the sound of his voice onscreen was pleasant – we won’t say, the ‘audio’ of his voice. And, we won’t say that the voice of the singer on the street had amazing ‘audio’. Instead, we would say that the ‘sound’ of his or her voice was amazing.

Whether the sound is natural or reproduced, the path to our ears is complex. You don’t need to know about most of that complexity, just like we don’t need to know about most of the complexity of the sound speaker on the wall.

But as a professional-in-training, you should understand enough so that you aren’t fooled by something that isn’t immediately obvious. You should be able to respond correctly if an audience member says something about the sound. For example, you could ask a appropriate question that will give the tech who will repair the problem better information.

Because your job is to tell the technician about negative changes in the sound – a rattle, a hum, no sound, distorted sound, sound that isn’t balanced (too much or too little from one side, for example)…and where…and if possible, why.

So, we’ll start slow. We’ll cover some basics. And after you hear a test DCP (See: What Does It Mean: DCP) in an auditorium a few times – or 10 or 20 times – you can review the material here to refine your knowledge. Perhaps you will find questions while you work that were presented already, but didn’t seem important before you refined your ability to notice things. When we do this, we are learning to evaluate by significance.

And, you can ask questions. Because no one was born with this data, everyone had to learn this. Much of it is new, and all of it has been refined very recently as science and technology has progressed.

The auditorium audio system
The Auditorium Audio System from the library system to the speakers – Ignore the parts under the purple boxes.

2 thoughts on “Audio (Sound Basics): Part 1

  1. Hola Jaun García,

    Very good eye! I made that drawing, derived from a larger one which included many cinema theaters. <https://cinematesttools.com/pdfs/DCinema_Auditoria_and_Equipment_Network_Generic.pdf> It was for a presentation many years ago and I put it in just for the joke because a serious point was made a little later.

    Then I kept it for the joke when I made the smaller drawing for a presentation 2 years ago <https://www.dcinematools.com/index.php?option=com_content&view=article&id=1879:loudness-in-cinema-ibc-2016-presentation&catid=114&Itemid=176>.

    Does the rest of the article make sense except for this joke?

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