Labels:animal | bird | book | bridge | bulletin board | canine | cat | daily | dog | door | earth | fence | mountain | plant | plaything | rock | sky | tree OCR: WHAT Is SOUND? OUND TRAVELS in waves, but it is hertz (Hz). The term frequency relers not part of the electromagnetic the number of waves produced per spectrum like light waves and radio variations in frequency that waves Sound produced when matter produce different pitches (high and low vibrates. frequency of these sounds). The limits of human hearing vibrations 1 measured units called are 20 Hz and 20 000 Hz Hearing limits Humans can bear sounds up to |Up to 35,000 Hz |Up to 120, ,000 Hz 20, 000 Hz. Other animals can bear much bigher pitched sounds Up to Up to 25 ,000 Hz 100 000 Hz DOPPLFE SPEED OLSO EFFECT SOUND refers second muct DOPPLEP ALSO