(ISNS) – Scientists don't fully understand how we detect faint sounds, because they should be drowned out by the background noise that the ear itself produces. Now, however, researchers at UCLA have produced clues to the process that allows us to hear a pin drop, or understand a whispered comment. They did so using hair cells taken from bullfrogs that they studied in laboratory glassware.
The UCLA team used an optical microscope and a high-speed camera to detect how the relationship between signals from faint sounds and bundles of the frogs' ear hairs differs from that between signals from louder sounds and the hair bundles.
Researchers in this field already knew that the hair cells synchronize with strong sound signals. They oscillate in phase with the incoming sounds; the louder the sound, the greater the degree of synchronization.
But in the case of the softest sounds, the UCLA team found, the cells intermitt
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