What's the difference between the left and right on a headphone? (Anders Jacobsen's blog)

January 11, 2007

What's the difference between the left and right on a headphone?

Mary from New York writes:

Hi Anders -- Don't know you, but saw your site and figured you might be willing & able to answer this question, even if it seems silly...

Headphones/earbuds are always marked as right or left. But why does it matter which earbud you put into which ear? I can see that some headphones are oriented only one way, but that doesn't apply to earbuds. Is there a difference if I switch ears? This sounds so basic that I ought to know it, but I don't!

Thanks --

Mary Federico

New York City

Mary, it's not a stupid question at all!

As you correctly identify, some earbuds and headphones will have a non-symmetric layout, adapted to fit your ear/head perfectly. Other, symmetric headphones (e.g. the default iPod earbuds, Etymotic and Shure noise-cancelling earbuds, many headsets) are completely symmetric and the L/R-indication has no impact on the physical fit in/on your ear.

However: all this said about the L and R buds being identical, many musicians and movie makers will use the stereo sound channels for sound effects aimed at one or the other ear. If you watch a film wearing heaphones the wrong way around (easily done, e.g. on a long distance flight) you'll probably quickly notice that 'something is wrong': cars appearing from the left on the screen, but the sound coming in from the right etc. Some music and some movies make more use of these effects than others, and for normal pop music it's rare that it would make any difference to you at all whether you put the buds in the 'right' or the 'wrong' ear.

Wikipedia says in the chapter on Stereophonic sound:

Most two-channel recordings are stereo recordings only in [a] weaker sense. Pop music, in particular, is usually recorded using close miking techniques, which artificially separates signals into several tracks. The separate tracks are then mixed into a two-channel recording which often bears little or no resemblance to the actual physical and spatial relationship of the musicians at the time of the original performance. Indeed, it is not uncommon for different tracks of the same song to be recorded at different times, and even in different studios, and then mixed into a final two-channel recording for commercial release. Classical music recordings are a notable exception.