People can tell if a sound is coming from their right or left, by the small delay of the sound reaching their ears. How do people recognise if a sound comes from above or below?

Question

People can tell if a sound is coming from their right or left, by the small delay of the sound reaching their ears. How do people recognise if a sound comes from above or below?

In: 222

Answer 1

By the shape of our ears. The top 1/2 of our ears don’t look the same as the bottom 1/2.

SmarterEveryDay has a video on this, including a fun little experiment showing that if you put playdoh on your outer ears, you no longer can discern these things (4:30 mark):

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It also isn’t just a delay difference between the ears, it also is an volume difference and a frequency difference caused by the sound wrapping around our skull.

Head Related Transfer Functions (HRTFs) are very important in getting headphones to sound right (especially in-ears) and super important to get spatial audio to sound right.

When Sony announced spatial audio for the PlayStation, they showed the insane rig they used to measure an individual’s HRTF: