Blog: NVH, sound engineering
Dave Leggett | 14 February 2007
The sub-conscious is a fascinating and slightly scary subject area. I guess it's slightly scary because we're not all that sure about what's going on inside our heads. The human mind is a complex thing. Just think about the multi-tasking going on as you drive a car. You don't even have to think about depressing the clutch when changing gear and, as you work your legs and arms to drive, your brain is also processing a relentless barrage of information through your body's physical sensors.
And you can still find spare brain RAM to consider Arsenal's chances against Bolton Wanderers in the Cup and what's for dinner tonight. Give yourself a pat on the back.
What do you hear as you drive? Plenty. Acoustic engineering is an important element in automobile/powertrain development.
As I whipped up an omelette in the kitchen the other day, a clever bloke from Ricardo was on the radio explaining how attuned, in our sub-conscious, we all are to automotive sounds (I have looked for a link to the programme, but can't find it, sorry). It's not just wanting to hear the visceral growl of a TVR (RIP), but we are conditioned to certain common sounds - types of sound and their pitch - inside the automobile cabin. Their abscence can be unsettling, in the same way as the true and relentless quiet that you get way out in the wilderness which is devoid of the urban background noise that we don't even consciously notice.
Here's another thing. When you cross the road, as a pedestrian, what senses do you use? Mainly sight I should think, but your ears are working and alert too. Cars make a sound - part 'road noise' (tyre friction with road surface) and part powertrain. You see the approaching car, but you hear it also. What if the noise was reduced by 80% because the car has no ICE and what if your sight is poor or non-existent?
Should cars driven by relatively quiet electric motors be forced to make a compensatory noise of some sort? How irritating would constantly beeping electric cars be (a small price to pay for lives saved, perhaps)?
Could be a future aftermarket opportunity though.
'Say goodbye to those electric vehicle beeping blues with the revolutionary cartune. Installed in seconds, cartune will ensure that you are wafted along to a melody of tasteful pre-loaded tunes that are sure to raise a smile from passers-by including Dixie, the Star Wars theme tune and Rule Britannia.'
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