Scientists marvel over ear’s intricate design
INTELLIGENT DESIGN | Researchers studying the detection of localized sound discover precise and complicated process
by Julie Borg; WORLD MAGAZINE
For most of the day, our ears and brains work together to tell us what direction the sounds we hear are coming from. A mother immediately looks in the direction of a crying child because her brain has localized the sound and can tell exactly where her child is. It happens so automatically she doesn’t even think about it. But the process of sound localization has been a mystery to researchers, until now.
We hear because sound waves strike our eardrums and cause them to vibrate. We are able to localize sound because the sound waves emanating from a certain place will not strike both eardrums at exactly the same time. The time interval between the sound waves striking one eardrum and then the other is referred to as the interaural timing difference (ITD). Scientists have known for a long time that our brains interpret the ITD to tell us a sound’s direction. But the baffling mystery has been how that ITD, only millionths of second long, can remain stable and consistent as the auditory signals travel through neurons on their way to the auditory cortex.
Researchers at the Ludwig-Maximilian University of Munich just found the answer by studying the process in gerbils and mice. Their study, published in the Proceedings of the National Academy of Sciences, details multiple and very intricate, precisely timed processes that must work together to preserve the ITDs as they travel from the ear drum all the way to the brain’s processing center.
This “neuronal processing requires exceptional temporal precision,” according to the researchers. It’s exactly the kind of precision that points to the creative design or our God, not the random mutations of Darwinian natural selection.