January 7, 2011

McGurk effect - can you trust your ears?

Here is an effect that will surprise you. It's called the McGurk effect. See it for yourself:

Audio implications

So what does this mean for audio? It illustrates one thing we should have admitted all along - that we can't fully trust our ears. Sure, when we hear a sound system we like, our ears aren't lying. However, it pays not to believe everything your ears will tell you. The important thing to realise is that what we hear is processed by a powerful computer. It's very good at processing some things, not so good at others. In this case, when it comes to speech recognition, what is seen can over ride what is heard. The interesting thing is that this effect is robust enough to occur even when we know about it. It isn't like visual illusions that work only until you realise what is going on.

High end audio

Consider high end audio components. Is there a real acoustic benefit to having a 10mm thick brushed aluminium face plate? Or do ultra thick speaker cables sound better? Somehow a 20mm thick cable looks like it should perform better in some way. I recall hearing of one particular company that sold very expensive power cables who used garden hose to make them thicker. I suspect there are two benefits here. One is that the manufacturer can increase their profit because consumers will pay a great deal more for the perceived benefits. The other is that those who buy them will believe they hear a difference. This isn't the McGurk effect, but rather it's the brain displaying it's talent for pattern recognition. Listen to the same piece of music twice and if you have an emotionally compelling reason to hear it different, and you believe there is a genuine difference, you will hear a difference even if it doesn't exist. I call this the "man in the moon" effect. There isn't a man in the moon, our brain just finds a pattern. The same is true with music. There is also a self-generated chemical reward system where the belief that something is better stimulates the chemical reward system of the brain.

So what does all this mean?

If you want to believe, you will be tricked. Sales people want to sell. Other audio enthusiasts want you to back them up on what they feel sounds better. The question is, do you want to be sold? In many cases, the answer is yes. Audiophiles are always looking for an upgrade. There is of course nothing wrong with that, however, this usually means spending more money on the things that matter the least. The most likely reason is that they are the easy upgrades. It takes no skill or special knowledge to buy a cable based on a good review or a recommendation from an audio forum. However, the biggest improvements require you to invest in some audio education, or pay a professional.

Do you want to get some real improvements that are far bigger? One of the main goals of this blog is to help audiophiles get started on the bigger improvements. Acoustic treatments and speakers that interact better with the room is the best place to start.

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