Ghi ch\u00fa: T\u00e0i li\u1ec7u tr\u00edch d\u1eabn<\/p>\n\n\n\n
\u0110\u00e3 bao gi\u1edd c\u00e1c em t\u1ef1 h\u1ecfi, t\u1ea1i sao ch\u00fang ta c\u00f3 th\u1ec3 nghe \u0111\u01b0\u1ee3c nh\u1eefng \u00e2m thanh hay ch\u01b0a? Li\u1ec7u c\u00f3 ph\u1ea3i ch\u00fang ta \u0111\u1ec1u nghe \u0111\u01b0\u1ee3c h\u1ebft t\u1ea5t c\u1ea3 nh\u1eefng \u00e2m thanh c\u00f3 trong cu\u1ed9c s\u1ed1ng hay kh\u00f4ng? \u0110\u00e2y ch\u00ednh l\u00e0 m\u1ed9t ch\u1ee7 \u0111\u1ec1 c\u1ea7n \u0111\u01b0\u1ee3c gi\u1ea3i \u0111\u00e1p d\u00e0nh cho c\u00e1c em l\u1edbp 7. Tr\u00ean th\u1ef1c t\u1ebf, \u0111\u1ed9 to c\u1ee7a \u00e2m \u1ea3nh h\u01b0\u1edfng r\u1ea5t nhi\u1ec1u \u0111\u1ebfn vi\u1ec7c nghe n\u00f3i. Cu\u1ed9c s\u1ed1ng h\u1eb1ng ng\u00e0y c\u1ee7a ch\u00fang ta c\u0169ng kh\u00f4ng ch\u1ec9 c\u00f3 t\u1eebng \u0111\u00f3 \u00e2m thanh. B\u00e0i vi\u1ebft ng\u00e0y h\u00f4m nay, ch\u00fang ta h\u00e3y c\u00f9ng nhau t\u00ecm hi\u1ec3u v\u1ec1 ch\u1ee7 \u0111\u1ec1 n\u00e0y v\u00e0 gi\u1ea3i \u0111\u00e1p c\u00e1c hi\u1ec7n t\u01b0\u1ee3ng trong cu\u1ed9c s\u1ed1ng nh\u00e9!<\/p>\n\n\n\n
Th\u00ed nghi\u1ec7m v\u1ec1 \u0111\u1ed9 to<\/p>\n\n\n\n
Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng \u2013 \u0111\u1ed9 to c\u1ee7a \u00e2m<\/p>\n\n\n\n
Tr\u01b0\u1edbc khi \u0111\u1ebfn v\u1edbi nh\u1eefng gi\u1ea3i \u0111\u00e1p \u0111\u1ed9 to c\u1ee7a \u00e2m l\u00e0 g\u00ec, ch\u00fang ta c\u1ea7n ph\u1ea3i hi\u1ec3u v\u1ec1 dao \u0111\u1ed9ng. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u00f3 \u1ea3nh h\u01b0\u1edfng r\u1ea5t nhi\u1ec1u \u0111\u1ebfn \u0111\u1ed9 to c\u1ee7a \u00e2m. Ch\u00ednh v\u00ec v\u1eady, hi\u1ec3u \u0111\u01b0\u1ee3c v\u1ec1 \u0111i\u1ec1u n\u00e0y, ch\u00fang ta s\u1ebd t\u00ecm hi\u1ec3u d\u1ec5 d\u00e0ng h\u01a1n. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng \u0111\u01b0\u1ee3c bi\u1ebft \u0111\u1ebfn l\u00e0 \u0111\u1ed9 l\u1ec7ch l\u1edbn nh\u1ea5t c\u1ee7a v\u1eadt so v\u1edbi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. N\u00f3i theo m\u1ed9t c\u00e1ch kh\u00e1c, trong qu\u00e1 tr\u00ecnh giao \u0111\u1ed9ng, \u0111\u1ed9 l\u1ec7ch l\u1edbn nh\u1ea5t c\u1ee7a v\u1eadt so v\u1edbi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng c\u1ee7a v\u1eadt \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 bi\u00ean \u0111\u1ed9 giao \u0111\u1ed9ng.<\/p>\n\n\n\n
Theo nh\u1eefng th\u00ed nghi\u1ec7m c\u1ee7a c\u00e1c nh\u00e0 v\u1eadt l\u00fd cho bi\u1ebft, bi\u00ean \u0111\u1ed9 giao \u0111\u1ed9ng c\u00e0ng l\u1edbn th\u00ec \u00e2m do v\u1eadt \u0111\u00f3 ph\u00e1t ra c\u00e0ng to. Ch\u00ednh v\u00ec v\u1eady, ch\u00fang ta c\u00f3 th\u1ec3 n\u00f3i, \u0111\u1ed9 to c\u1ee7a \u00e2m ph\u1ee5 thu\u1ed9c v\u00e0o bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt. Ng\u01b0\u1ee3c l\u1ea1i, khi bi\u00ean \u0111\u1ed9 giao \u0111\u1ed9ng c\u00e0ng nh\u1ecf, th\u00ec v\u1eadt ph\u00e1t ra \u00e2m thanh c\u00e0ng b\u00e9. Trong cu\u1ed9c s\u1ed1ng, ch\u00fang ta c\u00f3 th\u1ec3 d\u1ec5 d\u00e0ng nh\u1eadn ra \u0111i\u1ec1u n\u00e0y. T\u1eeb nh\u1eefng thay \u0111\u1ed5i c\u1ee7a v\u1eadt, ch\u00fang ta c\u00f3 th\u1ec3 hi\u1ec3u \u0111\u01b0\u1ee3c v\u1ec1 bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng.<\/p>\n\n\n\n
Ch\u1eafc h\u1eb3n c\u00e1c b\u1ea1n \u0111\u00e3 t\u1eebng th\u1ea5y chi\u1ebfc tr\u1ed1ng tr\u01b0\u1eddng \u0111\u00fang kh\u00f4ng n\u00e0o? Khi \u0111\u1ec3 y\u00ean, m\u1eb7t tr\u1ed1ng \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Khi b\u00e1c b\u1ea3o v\u1ec7 d\u00f9ng d\u00f9i tr\u1ed1ng \u0111\u00e1nh v\u00e0o m\u1eb7t tr\u1ed1ng. M\u1eb7t tr\u1ed1ng di chuy\u1ec3n t\u1ea1o th\u00e0nh nh\u1eefng bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng. \u0110i\u1ec1u n\u00e0y \u0111em \u0111\u1ebfn ti\u1ebfng vang l\u1edbn t\u1eeb chi\u1ebfc tr\u1ed1ng. Hay ch\u00fang ta c\u00f2n g\u1ecdi \u00e2m thanh n\u00e0y ch\u00ednh l\u00e0 ti\u1ebfng tr\u1ed1ng tr\u01b0\u1eddng. M\u1eb7t tr\u1ed1ng dung chuy\u1ec3n c\u00e0ng nhi\u1ec1u th\u00ec \u00e2m thanh n\u00e0y c\u00e0ng to. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng \u1ea3nh h\u01b0\u1edfng tr\u1ef1c ti\u1ebfp \u0111\u1ebfn \u0111\u1ed9 to c\u1ee7a \u00e2m t\u1eeb v\u1eadt ph\u00e1t ra. Khi v\u1eadt \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng b\u1eb1ng kh\u00f4ng v\u00e0 kh\u00f4ng g\u00e2y ra \u00e2m thanh.<\/p>\n\n\n\n
Ki\u1ebfn th\u1ee9c \u0111\u1ed9 to c\u1ee7a \u00e2m kh\u00f4ng kh\u00f3<\/p>\n\n\n\n
\u0110\u1ed9 to c\u1ee7a \u00e2m l\u00e0 g\u00ec?<\/p>\n\n\n\n
Sau khi \u0111\u00e3 hi\u1ec3u \u0111\u01b0\u1ee3c v\u1ec1 bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng h\u00ecnh th\u00e0nh l\u00ean \u00e2m thanh. Ch\u00fang ta s\u1ebd c\u00f9ng nhau t\u00ecm hi\u1ec3u v\u1ec1 \u0111\u1ed9 to c\u1ee7a \u00e2m thanh. \u0110\u1ed9 to \u00e2m \u0111\u01b0\u1ee3c \u0111o b\u1eb1ng \u0111\u01a1n v\u1ecb \u0111\u00eaxiben (k\u00ed hi\u1ec7u l\u00e0 dB). \u0110\u00e2y l\u00e0 \u0111\u01a1n v\u1ecb quy \u01b0\u1edbc \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 \u0111o \u0111\u1ed9 l\u1edbn c\u1ee7a \u00e2m thanh. Khi c\u00e1c em h\u1ecdc t\u1eadp<\/a> v\u00e0 t\u00ednh to\u00e1n tr\u00ean l\u1edbp c\u0169ng s\u1ebd s\u1eed d\u1ee5ng \u0111\u1ebfn \u0111\u01a1n v\u1ecb n\u00e0y. Ngo\u00e0i dB c\u00f2n c\u00f3 r\u1ea5t nhi\u1ec1u \u0111\u01a1n v\u1ecb kh\u00e1c d\u00f9ng \u0111\u1ec3 \u0111o \u00e2m thanh. C\u00e1c em s\u1ebd \u0111\u01b0\u1ee3c t\u00ecm hi\u1ec3u k\u1ef9 c\u00e0ng h\u01a1n trong b\u1ea3ng quy \u0111\u1ed5i tr\u00ean l\u1edbp.<\/p>\n\n\n\n Ch\u00fang ta c\u00f3 th\u1ec3 nghe \u0111\u01b0\u1ee3c c\u00e1c \u00e2m thanh nh\u1ecf, to kh\u00e1c nhau. Tuy nhi\u00ean \u0111\u1ec3 \u0111o \u0111\u1ed9 l\u1edbn c\u1ee7a \u00e2m thanh, ng\u01b0\u1eddi ta c\u1ea7n ph\u1ea3i s\u1eed d\u1ee5ng m\u00e1y chuy\u00ean d\u1ee5ng. C\u00e1c \u00e2m thanh kh\u00e1c nhau c\u00f3 \u0111\u1ed9 to nh\u1ecf kh\u00e1c nhau. V\u00ed d\u1ee5 ti\u1ebfng n\u00f3i chuy\u1ec7n th\u00ec th\u1ea7m s\u1ebd c\u00f3 \u0111\u1ed9 l\u1edbn \u00e2m thanh nh\u1ecf h\u01a1n ti\u1ebfng h\u00e9t. \u0110\u1ed9 l\u1edbn c\u1ee7a nh\u1eefng \u00e2m thanh n\u00e0y l\u00e0 bao nhi\u00eau, ch\u00fang ta c\u1ea7n ph\u1ea3i s\u1eed d\u1ee5ng m\u00e1y \u0111o.<\/p>\n\n\n\n Tai ng\u01b0\u1eddi ch\u00fang ta c\u0169ng ch\u1ec9 c\u00f3 th\u1ec3 nghe \u0111\u01b0\u1ee3c m\u1ed9t s\u1ed1 \u00e2m thanh c\u00f3 \u0111\u1ed9 l\u1edbn nh\u1ea5t \u0111\u1ecbnh. N\u1eb1m ngo\u00e0i kho\u1ea3ng \u0111\u1ed9 l\u1edbn n\u00e0y, tai ng\u01b0\u1eddi kh\u00f4ng th\u1ec3 nghe \u0111\u01b0\u1ee3c. \u0110\u1ed9 to c\u1ee7a \u00e2m ph\u00f9 h\u1ee3p v\u1edbi tai ng\u01b0\u1eddi l\u00e0 kho\u1ea3ng 70dB. N\u1ebfu \u00e2m thanh to h\u01a1n 70dB tai ng\u01b0\u1eddi ch\u00fang ta c\u00f3 th\u1ec3 nghe r\u00f5 h\u01a1n. Tuy nhi\u00ean nghe \u00e2m thanh qu\u00e1 to, ho\u1eb7c trong th\u1eddi gian d\u00e0i c\u00f3 th\u1ec3 g\u00e2y kh\u00f3 ch\u1ecbu. Nh\u1eefng hi\u1ec7n t\u01b0\u1ee3ng \u0111i\u1ebfc tai v\u00ec \u00e2m thanh qu\u00e1 l\u1edbn ch\u00ednh l\u00e0 \u0111\u1ed9 to c\u1ee7a \u00e2m thanh \u0111\u00f3 \u0111\u00e3 v\u01b0\u1ee3t qu\u00e1 ng\u01b0\u1ee1ng cho ph\u00e9p. \u0110\u1ed9 to c\u1ee7a \u00e2m \u1edf m\u1ee9c 70dB g\u1ecdi l\u00e0 gi\u1edbi h\u1ea1n v\u1ec1 \u00f4 nhi\u1ec5m ti\u1ebfng \u1ed3n.<\/p>\n\n\n\n Khi \u0111\u1ed9 to c\u1ee7a \u00e2m b\u1eb1ng hay l\u1edbn h\u01a1n 130dB, \u00e2m thanh \u0111\u00e3 tr\u1edf n\u00ean qu\u00e1 to. \u00c2m thanh nh\u01b0 v\u1eady s\u1ebd l\u00e0m cho tai nh\u1ee9c nh\u1ed1i r\u1ea5t kh\u00f3 ch\u1ecbu v\u00e0 c\u00f3 th\u1ec3 l\u00e0m \u0111i\u1ebfc tai. V\u1eady \u0111\u1ed9 to c\u1ee7a \u00e2m \u1edf m\u1ee9c 130 dB g\u1ecdi l\u00e0 ng\u01b0\u1ee1ng \u0111au c\u00f3 th\u1ec3 l\u00e0m \u0111i\u1ebfc tai.<\/p>\n\n\n\n B\u1ea3ng \u0111\u1ed9 to c\u1ee7a \u00e2m thanh<\/p>\n\n\n\n Nh\u01b0 ch\u00fang ta \u0111\u00e3 \u0111\u1ec1 c\u1eadp \u0111\u1ebfn \u1edf tr\u00ean, m\u1ed7i \u00e2m thanh \u0111\u1ec1u c\u00f3 \u0111\u1ed9 to kh\u00e1c nhau. Ch\u00ednh v\u00ec v\u1eady, l\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 ch\u00fang ta bi\u1ebft \u00e2m thanh \u0111\u00f3 c\u00f3 \u0111\u1ed9 to l\u00e0 bao nhi\u00eau. C\u00e1c nh\u00e0 v\u1eadt l\u00fd h\u1ecdc \u0111\u00e3 nghi\u00ean c\u1ee9u v\u00e0 cho ra b\u1ea3ng \u0111\u1ed9 to c\u1ee7a \u00e2m d\u1ef1a tr\u00ean nh\u1eefng \u00e2m thanh th\u00f4ng d\u1ee5ng. C\u00e1c em c\u00f3 th\u1ec3 tham kh\u1ea3o ngay d\u01b0\u1edbi \u0111\u00e2y nh\u00e9!<\/p>\n\n\n\n Ti\u1ebfng n\u00f3i th\u00ec th\u1ea7m 20dB<\/p>\n\n\n\n Ti\u1ebfng n\u00f3i chuy\u1ec7n b\u00ecnh th\u01b0\u1eddng 40dB<\/p>\n\n\n\n Ti\u1ebfng nh\u1ea1c to 60dB<\/p>\n\n\n\n Ti\u1ebfng \u1ed3n r\u1ea5t to \u1edf ngo\u00e0i ph\u1ed1 80dB<\/p>\n\n\n\n Ti\u1ebfng \u1ed3n c\u1ee7a m\u00e1y m\u00f3c n\u1eb7ng trong c\u00f4ng x\u01b0\u1edfng 100dB<\/p>\n\n\n\n Ti\u1ebfng s\u00e9t 120dB<\/p>\n\n\n\n Ng\u01b0\u1ee1ng \u0111au (l\u00e0m \u0111au nh\u1ee9c tai), Ti\u1ebfng \u0111\u1ed9ng c\u01a1 ph\u1ea3n l\u1ef1c (\u1edf c\u00e1ch 4m) 130dB<\/p>\n\n\n\n \u0110\u00e2y ch\u00ednh l\u00e0 b\u1ea3ng s\u1ed1 \u0111o \u0111\u1ed9 to c\u1ee7a \u00e2m th\u01b0\u1eddng c\u00f3 trong cu\u1ed9c s\u1ed1ng. Ngo\u00e0i ra, xung quanh ta c\u00f2n c\u00f3 r\u1ea5t nhi\u1ec1u \u00e2m thanh to nh\u1ecf kh\u00e1c nhau. Tai ch\u00fang ta ch\u1ec9 c\u00f3 th\u1ec3 nghe \u0111\u01b0\u1ee3c nh\u1eefng \u00e2m thanh trong ng\u01b0\u1ee1ng cho ph\u00e9p. \u0110\u00f3 ch\u00ednh l\u00e0 l\u00fd do v\u00ec sao, c\u00f3 nhi\u1ec1u \u00e2m thanh khi ch\u00fang ta nghe th\u1ea5y c\u00f3 th\u1ec3 g\u00e2y kh\u00f3 ch\u1ecbu. \u0110i\u1ec1u n\u00e0y l\u00e0 v\u00ec \u0111\u1ed9 l\u1edbn c\u1ee7a \u00e2m thanh \u0111\u00e3 v\u01b0\u1ee3t ng\u01b0\u1ee1ng cho ph\u00e9p. Kh\u00f4ng n\u00ean c\u1ed1 g\u1eafng nghe nh\u1eefng \u00e2m thanh qu\u00e1 to trong th\u1eddi gian d\u00e0i. Nh\u01b0 v\u1eady, tai c\u1ee7a ch\u00fang ta c\u00f3 th\u1ec3 b\u1ecb t\u1ed5n th\u01b0\u01a1ng n\u1eb7ng.<\/p>\n\n\n\n \u0110\u1ed9 to n\u00e0o g\u00e2y kh\u00f3 ch\u1ecbu<\/p>\n\n\n\n M\u1ed9t s\u1ed1 d\u1ea1ng b\u00e0i t\u1eadp v\u1ec1 \u0111\u1ed9 to c\u1ee7a \u00e2m<\/p>\n\n\n\n C\u00e1c em s\u1ebd g\u1eb7p r\u1ea5t nhi\u1ec1u d\u1ea1ng b\u00e0i v\u1ec1 \u0111\u1ed9 to \u00e2m tr\u00ean l\u1edbp. Nh\u1eefng b\u00e0i t\u1eadp n\u00e0y \u0111\u1ec1u d\u1ef1a tr\u00ean nh\u1eefng nguy\u00ean l\u00fd c\u01a1 b\u1ea3n c\u1ee7a ch\u1ee7 \u0111\u1ec1 n\u00e0y. C\u00e1c em ch\u1ec9 c\u1ea7n h\u1ecdc k\u1ef9 l\u00fd thuy\u1ebft t\u1eeb \u0111\u00f3 bi\u1ebft c\u00e1ch v\u1eadn d\u1ee5ng v\u00e0o b\u00e0i t\u1eadp. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 d\u1ea1ng b\u00e0i c\u00e1c em th\u01b0\u1eddng g\u1eb7p. C\u00e1c em h\u00e3y \u0111\u1ecdc tham kh\u1ea3o v\u00e0 ghi nh\u1edb c\u00e1ch l\u00e0m b\u00e0i nh\u00e9!<\/p>\n\n\n\n D\u1ea1ng 1. X\u00e1c \u0111\u1ecbnh bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng.<\/p>\n\n\n\n D\u1ef1a v\u00e0o \u0111\u1ecbnh ngh\u0129a bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng.<\/p>\n\n\n\n L\u01b0u \u00fd: Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng l\u00e0 \u0111\u1ed9 l\u1ec7ch l\u1edbn nh\u1ea5t c\u1ee7a v\u1eadt so v\u1edbi v\u1ecb tr\u00ed \u0111\u1ee9ng y\u00ean c\u00e2n b\u1eb1ng ban \u0111\u1ea7u ch\u1ee9 kh\u00f4ng ph\u1ea3i l\u00e0 kho\u1ea3ng c\u00e1ch l\u1edbn nh\u1ea5t c\u1ee7a v\u1eadt so v\u1edbi v\u1ecb tr\u00ed \u0111\u1ee9ng y\u00ean c\u00e2n b\u1eb1ng.<\/p>\n\n\n\n Nh\u1eefng b\u00e0i t\u1eadp d\u1ea1ng n\u00e0y th\u01b0\u1eddng s\u1ebd li\u00ean quan \u0111\u1ebfn con l\u1eafc. C\u00e1c em s\u1ebd ph\u1ea3i quan s\u00e1t v\u1ecb tr\u00ed v\u00e0 t\u00ecm ra \u0111\u01b0\u1ee3c bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng l\u1edbn nh\u1ea5t ch\u00ednh l\u00e0 kho\u1ea3ng c\u00e1ch c\u1ee7a con l\u1eafc c\u00e1ch xa nh\u1ea5t so v\u1edbi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. C\u00e1c em h\u00e3y ch\u00fa \u00fd \u0111\u1ebfn nh\u1eefng g\u1ee3i \u00fd \u0111\u1ec1 b\u00e0i \u0111\u01b0a ra nh\u00e9!<\/p>\n\n\n\n D\u1ea1ng 2. Gi\u1ea3i th\u00edch m\u1ed9t s\u1ed1 hi\u1ec7n t\u01b0\u1ee3ng trong \u0111\u1eddi s\u1ed1ng th\u1ef1c t\u1ebf<\/p>\n\n\n\n D\u1ef1a v\u00e0o \u0111\u1eb7c \u0111i\u1ec3m<\/p>\n\n\n\n Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt c\u00e0ng l\u1edbn th\u00ec \u00e2m ph\u00e1t ra c\u00e0ng to<\/p>\n\n\n\n Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt c\u00e0ng nh\u1ecf th\u00ec \u00e2m ph\u00e1t ra c\u00e0ng nh\u1ecf<\/p>\n\n\n\n H\u1ea7u h\u1ebft nh\u1eefng b\u00e0i t\u1eadp trong ch\u01b0\u01a1ng tr\u00ecnh v\u1eadt l\u00fd 7 c\u1ee7a c\u00e1c em \u0111\u1ec1u s\u1ebd li\u00ean quan \u0111\u1ebfn bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng. Thay v\u00ec x\u00e1c \u0111\u1ecbnh \u00e2m thanh c\u1ee7a v\u1eadt th\u00ec c\u00e1c em s\u1ebd \u0111\u01b0\u1ee3c h\u1ecfi v\u1ec1 bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng nhi\u1ec1u h\u01a1n. N\u1eafm ch\u1eafc l\u00fd thuy\u1ebft s\u1ebd gi\u00fap c\u00e1c em l\u00e0m b\u00e0i t\u1ed1t h\u01a1n.<\/p>\n\n\n\n D\u1ea1ng 3. X\u00e1c \u0111\u1ecbnh \u00e2m thanh<\/p>\n\n\n\n D\u1ef1a v\u00e0o gi\u1edbi h\u1ea1n v\u1ec1 \u00f4 nhi\u1ec5m ti\u1ebfng \u1ed3n (70dB) v\u00e0 ng\u01b0\u1ee1ng \u0111au (130dB). T\u1eeb \u0111\u00f3 x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c \u00e2m thanh n\u00e0o c\u00f3 th\u1ec3 nghe \u0111\u01b0\u1ee3c b\u00ecnh th\u01b0\u1eddng. \u00c2m thanh n\u00e0o kh\u00f4ng th\u1ec3 nghe \u0111\u01b0\u1ee3c m\u00e0 g\u00e2y \u1ea3nh h\u01b0\u1edfng x\u1ea5u \u0111\u1ebfn s\u1ee9c kh\u1ecfe \u0111\u1ec3 c\u00f3 ph\u01b0\u01a1ng \u00e1n b\u1ea3o v\u1ec7 tai c\u1ee7a ch\u00fang ta. \u0110\u00e2y l\u00e0 d\u1ea1ng b\u00e0i k\u1ebft h\u1ee3p th\u1ef1c t\u1ebf cu\u1ed9c s\u1ed1ng. C\u00e1c em c\u1ea7n n\u1eafm ch\u1eafc gi\u1edbi h\u1ea1n \u0111\u1ed9 l\u1edbn \u00e2m thanh. T\u1eeb \u0111\u00f3 v\u1eadn d\u1ee5ng v\u00e0o b\u00e0i t\u1eadp th\u1ef1c t\u1ebf nh\u00e9!<\/p>\n\n\n\n Th\u00f4ng tin \u0111\u1ed9 to c\u1ee7a \u00e2m<\/p>\n\n\n\n C\u00f3 th\u1ec3 n\u00f3i nh\u1eefng ki\u1ebfn th\u1ee9c li\u00ean quan \u0111\u1ebfn ch\u1ee7 \u0111\u1ec1 \u0111\u1ed9 to c\u1ee7a \u00e2m \u0111\u00e3 \u0111\u01b0\u1ee3c ch\u00fang t\u00f4i \u0111\u1ec1 c\u1eadp \u0111\u1ebfn trong b\u00e0i vi\u1ebft n\u00e0y. Nh\u1eefng v\u00ed d\u1ee5 th\u1ef1c t\u1ebf v\u00e0 l\u00fd thuy\u1ebft \u0111\u01b0\u1ee3c ch\u00fang t\u00f4i gi\u1edbi thi\u1ec7u song song v\u1edbi nhau. Hy v\u1ecdng c\u00e1c em c\u00f3 th\u1ec3 ghi nh\u1edb m\u1ed9t c\u00e1ch d\u1ec5 d\u00e0ng. C\u00e1c em c\u00f3 th\u1ec3 ghi ch\u00e9p l\u1ea1i \u0111\u1ec3 h\u1ecdc t\u1eadp<\/a>, th\u1ef1c h\u00e0nh t\u1ed1t h\u01a1n. \u0110\u1eebng qu\u00ean<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":" Ghi ch\u00fa: T\u00e0i li\u1ec7u tr\u00edch d\u1eabn \u0110\u00e3 bao gi\u1edd c\u00e1c em t\u1ef1 h\u1ecfi, t\u1ea1i sao ch\u00fang ta c\u00f3 th\u1ec3 nghe \u0111\u01b0\u1ee3c nh\u1eefng \u00e2m thanh hay ch\u01b0a? Li\u1ec7u c\u00f3 ph\u1ea3i ch\u00fang ta \u0111\u1ec1u nghe \u0111\u01b0\u1ee3c h\u1ebft t\u1ea5t c\u1ea3 nh\u1eefng \u00e2m thanh c\u00f3 trong cu\u1ed9c s\u1ed1ng hay kh\u00f4ng? \u0110\u00e2y ch\u00ednh l\u00e0 m\u1ed9t ch\u1ee7 \u0111\u1ec1 c\u1ea7n \u0111\u01b0\u1ee3c gi\u1ea3i […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[4,7],"tags":[],"class_list":["post-1201","post","type-post","status-publish","format-standard","hentry","category-trung-hoc","category-vat-ly"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/1201","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=1201"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/1201\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=1201"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=1201"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=1201"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}