Simon Price
Dipping your toe into the world of audio forums, it’s sometimes hard to know what is porkies and what isn’t. Carte Blanche responses to ‘your DAC measures the same as another, so you must be hearing things’ – not that all audio can be measured as to quality; is to then start bandying about bias and the McGurk effect. A swamp of murkiness and muddiness in thought, just like mismatched amps and speakers, is to sound. But you know, we know, we all know, whether we really dig a HiFi component or not….
McGurk is an interesting study of ourselves and what we don’t quite appreciate to be true. Just like sitting with family members and seeing (well hearing) where discernible test tones cut off, with age related hearing loss pervading hearing acuity. Can we apply McGurk to audiophile HiFi in any way?
Teaching you how to suck eggs in describing what the McGurk effect is? Maybe, but a quick recap and it’s damn quirky… McGurk defines a categorical change in auditory perception induced by incompatible visual speech, resulting in a perception of hearing something other than what the voice is saying. So breaking this down into real world visualization……sorry…….If someone says ‘bar bar bar’ and the visual cues of mouth pronunciation, with lips together to pronounce B, is synchronized to acoustically present ‘bar bar bar’, you’ll clearly hear ‘bar bar bar’ too. The senses are aligned, no tomfoolery brain trickery is going on. Overdub the same ‘bar bar bar’ with a shot of the mouth pronouncing ‘var var var’ with teeth starting on the lower lip to make the ‘V’ sound, and you will probably hear ‘var var var’. Close your eyes and magic – ‘bar bar bar’ comes back and you can’t ‘self aware’ this visual/auditory trick away when looking back!
The effect doesn’t affect everyone in the same way and sometimes syllable sounds from visual and auditory cues can be combined – the so called fusion effect. In addition it has been found that skilled musicians are not so much susceptible to the McGurk effect, based on a hypothesis of having finer auditory or attentional musical ability, so as Audiophiles it is quite possible we are in a similar bracket?
By taking multi-modal sensory information this way, through human evolution it’s unsurprising that we’ve come to rely more on our visual environment, when in sensory conflict. Whatever the state of mind, these are weird perceptions. Caveman A needed his mince pies against Dinosaur B, remember.
The same is true sitting at a train station platform next to another stationary train with the other train moving off. Wait, we are moving?….until it passes and leaves you in a momentary head-jam, like a bad punchline to a joke. You realize you haven’t moved. Again an example of visual information overriding nil ‘seat of the pants’ sensory motion and no sensing acceleration in the inner ear too. Same with the rubber hand experiment;
But everything is way up in the air, when an audio website proclaims, infers, suggests or plants seeds – whatever words you want to use, that sights dominance over sound, is unexceptional and without exclusion. That somehow by eyeballing our new sparkly amplifier with branded logo, we are influenced sight over sound into hearing audio better. A crazy argument, that would put us in a messed up degraded sensory head spin of a world, akin to being Kim Jong-Un’s farmer and dentist all in one. It would be akin to being on a constant LSD trip. No, no, no.
The operative words are “sensory conflict”, since where presented with discrepant sensory information, the brain makes sense of what is most congruent. Not when we enjoy the status quo with no conflict aside from some auditory perceptions – such as The Tritone Paradox or Phoneme Restoration effect. It it’s hard to make a case that the quality of the audio we hear is being adversely affected by our brain pathways. We know the brain relates sounds we hear from our ears to our auditory cortex in forming pathways in the recognition of sounds. Just like noticing familiar friends. But during a startle response it also makes us think we hear sounds if we’ve previously been in danger. The sound of a rustling plastic bag might remind us of a dangerous animal if annexed in proximate space, in memory bank thoughts. But how can I sit here and say that in the ordinary course of events, a drum can’t be discerned from a more realistically dynamic and timbrally accurate drum, in a non degraded environment, with no apparent visual/auditory contradiction going on? The simple truth is, I don’t think anyone could credibly say you can. We do know though that if you massively take out the transient information from music, an instrument can no longer sound like itself, but that’s far from our systems!
So if you hear it considerably better, then yes, I’ve some really obvious news for you….a complete revelatory shocker – you really do hear it better! To boot, most would never advocate buying pricey HiFi without a home trial EVER. Also upgrading when gaining good benefit. Then bias will be at sea because zeniths of performance will be comparable to eating a double decker versus a restaurant dish. You don’t need me to tell you there is no difference.
The approach to bias is admittedly a more nuanced one that can trick us into believing audio is better to a degree. The so called Placebo Effect. But it’s not the only catch all. I use my ‘umming and arring’ analogy on performance to keep bias at bay, and keep it simple. If you are ‘umming or arring’ then bias probably comes in. Opposingly, you’ll know you are onto a winner or not.
So we have the scope to be incredibly self aware as Audiophiles and in control of environments and not be hoodwinked into judgements and views without being alive to bias, or at least cognisant it is happening. To buy into a notion that bias is a silent killer of investment in HiFi or it means we can’t discern products apart, is a foolhardy and pessimistic reason not to try and find out. In HiFi there is a chance of relative ‘zero to hero’ improvement as well as ‘all the gear and no idea’ limiting scope. But to understand is the optimist approach and this means that misplacing the use of the McGurk effect is misguided.
Sources
- McDonald and McGurk (1976) – what is it.
- What is the McGurk Effect – Frontiers in Psychology
- BBC Horizon – video explanation of The McGurk effect and similar Rubber hand experiment.
- Science direct.com
- Mallick et al (2015) – some people don’t experience the McGurk effect
- John F. Magnotti, Michael S. Beauchamp. A Causal Inference Model Explains Perception of the McGurk Effect and Other Incongruent Audiovisual Speech. PLOS Computational Biology, 2017
- The threshold for the McGurk effect in audio-visual noise decreases with development – Rebecca J. Hirst, Jemaine E. Stacey, Lucy Cragg, Paula C. Stacey & Harriet A. Allen .
- Skilled musicians are not subject to the McGurk effect (2016) – Alice M. Proverbio, Gemma Massetti, Ezia Rizzi & Alberto Zani
