"We lost the 20,000s several years ago." refers to what whenshesmiles said about inaudible for adults frequencies.
Small children tend to have better hearing than adults and can hear sounds as low as 20 Hz (a large pipe organ) or as high as 20,000 Hz (a special dog whistle that most humans cannot hear). When hearing loss begins, a person will, generally, first have trouble hearing high-pitched noises.
"We lost the 20,000s several years ago." refers to what whenshesmiles said about inaudible for adults frequencies.
Small children tend to have better hearing than adults and can hear sounds as low as 20 Hz (a large pipe organ) or as high as 20,000 Hz (a special dog whistle that most humans cannot hear). When hearing loss begins, a person will, generally, first have trouble hearing high-pitched noises.