Finally there is some scientific research to explain mysteries like why some people cannot hear things that seem to be said in a perfectly audible volume to them. It has always perplexed people that what seems like a reasonable volume to them is sometimes inaudible or thunderous torture for someone else.
Research has revealed that kids can hear high-pitched noises, which adults can't. The House Ear Institute in Los Angeles has said that most adults' ability to hear high frequency noises disappears in "early middle age."
A Welsh security company has decided use this difference in hearing ability. They invented a high-pitched noise that would irritate teenagers but wouldn't be heard by adults. This devious invention known as the Mosquito was to make loitering kids disperse from storefronts without discouraging adults from shopping there.
Another study presented at this month's meeting of the Acoustical Society of America has revealed that non-Hispanic white people, in general, hear worse than other groups.
Secondly women, in general have been found to hear better than men. So this probably explains why a woman would call out, "I heard that!" when her man has just mumbled a disgruntled remark. Of course now women have their answer as to why a man who has been questioned why he didn't do something, he always seems to answer, "I never heard you ask me to do that."