{"id":47260,"date":"2023-04-22T00:30:54","date_gmt":"2023-04-22T05:30:54","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/how-to-record-ultrasonic-sounds\/"},"modified":"2025-01-21T07:21:24","modified_gmt":"2025-01-21T12:21:24","slug":"how-to-record-ultrasonic-sounds","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/vi\/how-to-record-ultrasonic-sounds\/","title":{"rendered":"H\u01b0\u1edbng d\u1eabn ghi \u00e2m si\u00eau \u00e2m hi\u1ec7u qu\u1ea3"},"content":{"rendered":"

\u00c2m thanh si\u00eau \u00e2m, v\u1edbi t\u1ea7n s\u1ed1 v\u01b0\u1ee3t qu\u00e1 ng\u01b0\u1ee1ng nghe c\u1ee7a con ng\u01b0\u1eddi, mang theo nhi\u1ec1u th\u00f4ng tin h\u1eefu \u00edch trong c\u00e1c l\u0129nh v\u1ef1c t\u1eeb y t\u1ebf, c\u00f4ng nghi\u1ec7p \u0111\u1ebfn nghi\u00ean c\u1ee9u khoa h\u1ecdc. Vi\u1ec7c ghi l\u1ea1i ch\u00ednh x\u00e1c \u00e2m thanh n\u00e0y \u0111\u00f2i h\u1ecfi thi\u1ebft b\u1ecb v\u00e0 k\u1ef9 thu\u1eadt chuy\u00ean bi\u1ec7t. B\u00e0i vi\u1ebft n\u00e0y s\u1ebd h\u01b0\u1edbng d\u1eabn chi ti\u1ebft c\u00e1ch th\u1ee9c ghi l\u1ea1i \u00e2m thanh si\u00eau \u00e2m m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3.<\/p>\n

Thi\u1ebft b\u1ecb c\u1ea7n thi\u1ebft<\/h3>\n

\u0110\u1ec3 ghi \u00e2m si\u00eau \u00e2m, b\u1ea1n c\u1ea7n m\u1ed9t microphone \u0111\u1eb7c bi\u1ec7t \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1ec3 thu nh\u1eadn t\u1ea7n s\u1ed1 cao, th\u01b0\u1eddng \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 microphone si\u00eau \u00e2m. M\u1ed9t s\u1ed1 microphone si\u00eau \u00e2m c\u00f3 th\u1ec3 thu \u0111\u01b0\u1ee3c t\u1ea7n s\u1ed1 l\u00ean \u0111\u1ebfn 100kHz ho\u1eb7c cao h\u01a1n. B\u00ean c\u1ea1nh \u0111\u00f3, b\u1ea1n c\u1ea7n m\u1ed9t b\u1ed9 khu\u1ebfch \u0111\u1ea1i t\u00edn hi\u1ec7u, v\u00ec t\u00edn hi\u1ec7u si\u00eau \u00e2m th\u01b0\u1eddng r\u1ea5t y\u1ebfu. Cu\u1ed1i c\u00f9ng, b\u1ea1n c\u1ea7n m\u1ed9t thi\u1ebft b\u1ecb ghi \u00e2m, c\u00f3 th\u1ec3 l\u00e0 m\u00e1y t\u00ednh v\u1edbi ph\u1ea7n m\u1ec1m chuy\u00ean d\u1ee5ng ho\u1eb7c m\u00e1y ghi \u00e2m k\u1ef9 thu\u1eadt s\u1ed1 h\u1ed7 tr\u1ee3 t\u1ea7n s\u1ed1 l\u1ea5y m\u1eabu cao.<\/p>\n\n\n\n\n\n\n\n
Thi\u1ebft b\u1ecb<\/th>\nCh\u1ee9c n\u0103ng<\/th>\nL\u01b0u \u00fd khi l\u1ef1a ch\u1ecdn<\/th>\n<\/tr>\n<\/thead>\n
Microphone si\u00eau \u00e2m<\/td>\nThu nh\u1eadn s\u00f3ng si\u00eau \u00e2m<\/td>\nCh\u00fa \u00fd d\u1ea3i t\u1ea7n s\u1ed1 h\u1ed7 tr\u1ee3, \u0111\u1ed9 nh\u1ea1y v\u00e0 h\u01b0\u1edbng t\u00ednh<\/td>\n<\/tr>\n
B\u1ed9 khu\u1ebfch \u0111\u1ea1i<\/td>\nKhu\u1ebfch \u0111\u1ea1i t\u00edn hi\u1ec7u si\u00eau \u00e2m<\/td>\nCh\u1ecdn b\u1ed9 khu\u1ebfch \u0111\u1ea1i c\u00f3 \u0111\u1ed9 \u1ed3n th\u1ea5p v\u00e0 d\u1ea3i t\u1ea7n ph\u00f9 h\u1ee3p<\/td>\n<\/tr>\n
Thi\u1ebft b\u1ecb ghi \u00e2m<\/td>\nL\u01b0u tr\u1eef d\u1eef li\u1ec7u \u00e2m thanh<\/td>\n\u0110\u1ea3m b\u1ea3o thi\u1ebft b\u1ecb h\u1ed7 tr\u1ee3 t\u1ea7n s\u1ed1 l\u1ea5y m\u1eabu \u0111\u1ee7 cao (\u00edt nh\u1ea5t g\u1ea5p \u0111\u00f4i t\u1ea7n s\u1ed1 si\u00eau \u00e2m cao nh\u1ea5t c\u1ea7n ghi)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Ph\u1ea7n m\u1ec1m ghi \u00e2m<\/h3>\n

C\u00f3 nhi\u1ec1u ph\u1ea7n m\u1ec1m ghi \u00e2m h\u1ed7 tr\u1ee3 ghi l\u1ea1i \u00e2m thanh si\u00eau \u00e2m. M\u1ed9t s\u1ed1 ph\u1ea7n m\u1ec1m ph\u1ed5 bi\u1ebfn cho ph\u00e9p t\u00f9y ch\u1ec9nh t\u1ea7n s\u1ed1 l\u1ea5y m\u1eabu v\u00e0 \u0111\u1ed9 ph\u00e2n gi\u1ea3i bit, gi\u00fap t\u1ed1i \u01b0u h\u00f3a ch\u1ea5t l\u01b0\u1ee3ng ghi \u00e2m. Quan tr\u1ecdng l\u00e0 ph\u1ea3i ch\u1ecdn ph\u1ea7n m\u1ec1m t\u01b0\u01a1ng th\u00edch v\u1edbi thi\u1ebft b\u1ecb ghi \u00e2m v\u00e0 h\u1ec7 \u0111i\u1ec1u h\u00e0nh c\u1ee7a b\u1ea1n.<\/p>\n

K\u1ef9 thu\u1eadt ghi \u00e2m<\/h3>\n

V\u1ecb tr\u00ed \u0111\u1eb7t microphone \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng trong vi\u1ec7c ghi \u00e2m si\u00eau \u00e2m. C\u1ea7n \u0111\u1eb7t microphone c\u00e0ng g\u1ea7n ngu\u1ed3n ph\u00e1t si\u00eau \u00e2m c\u00e0ng t\u1ed1t \u0111\u1ec3 gi\u1ea3m thi\u1ec3u nhi\u1ec5u v\u00e0 suy hao t\u00edn hi\u1ec7u. Ngo\u00e0i ra, m\u00f4i tr\u01b0\u1eddng ghi \u00e2m c\u0169ng \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn ch\u1ea5t l\u01b0\u1ee3ng \u00e2m thanh. N\u00ean ghi \u00e2m trong m\u00f4i tr\u01b0\u1eddng y\u00ean t\u0129nh, tr\u00e1nh c\u00e1c ngu\u1ed3n nhi\u1ec5u \u00e2m thanh kh\u00e1c. N\u1ebfu c\u1ea7n thi\u1ebft, c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng v\u1eadt li\u1ec7u h\u1ea5p th\u1ee5 \u00e2m thanh \u0111\u1ec3 gi\u1ea3m thi\u1ec3u ti\u1ebfng \u1ed3n xung quanh.<\/p>\n

X\u1eed l\u00fd t\u00edn hi\u1ec7u sau ghi \u00e2m<\/h3>\n

Sau khi ghi \u00e2m, b\u1ea1n c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng ph\u1ea7n m\u1ec1m chuy\u00ean d\u1ee5ng \u0111\u1ec3 ph\u00e2n t\u00edch v\u00e0 x\u1eed l\u00fd t\u00edn hi\u1ec7u si\u00eau \u00e2m. C\u00e1c ph\u1ea7n m\u1ec1m n\u00e0y cho ph\u00e9p b\u1ea1n l\u1ecdc nhi\u1ec5u, khu\u1ebfch \u0111\u1ea1i t\u00edn hi\u1ec7u, v\u00e0 hi\u1ec3n th\u1ecb t\u00edn hi\u1ec7u d\u01b0\u1edbi d\u1ea1ng s\u00f3ng ho\u1eb7c ph\u1ed5 t\u1ea7n. Vi\u1ec7c ph\u00e2n t\u00edch ph\u1ed5 t\u1ea7n gi\u00fap x\u00e1c \u0111\u1ecbnh c\u00e1c t\u1ea7n s\u1ed1 si\u00eau \u00e2m c\u00f3 m\u1eb7t trong t\u00edn hi\u1ec7u ghi \u0111\u01b0\u1ee3c.<\/p>\n

L\u01b0u \u00fd quan tr\u1ecdng<\/h3>\n

T\u1ea7n s\u1ed1 l\u1ea5y m\u1eabu c\u1ee7a thi\u1ebft b\u1ecb ghi \u00e2m ph\u1ea3i \u0111\u1ee7 cao \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o ghi l\u1ea1i \u0111\u01b0\u1ee3c to\u00e0n b\u1ed9 th\u00f4ng tin c\u1ee7a t\u00edn hi\u1ec7u si\u00eau \u00e2m. Theo \u0111\u1ecbnh l\u00fd Nyquist-Shannon, t\u1ea7n s\u1ed1 l\u1ea5y m\u1eabu ph\u1ea3i \u00edt nh\u1ea5t g\u1ea5p \u0111\u00f4i t\u1ea7n s\u1ed1 si\u00eau \u00e2m cao nh\u1ea5t c\u1ea7n ghi. V\u00ed d\u1ee5, n\u1ebfu mu\u1ed1n ghi \u00e2m si\u00eau \u00e2m \u1edf t\u1ea7n s\u1ed1 40kHz, t\u1ea7n s\u1ed1 l\u1ea5y m\u1eabu t\u1ed1i thi\u1ec3u ph\u1ea3i l\u00e0 80kHz.<\/p>\n

Vi\u1ec7c ghi l\u1ea1i \u00e2m thanh si\u00eau \u00e2m \u0111\u00f2i h\u1ecfi s\u1ef1 chu\u1ea9n b\u1ecb k\u1ef9 l\u01b0\u1ee1ng v\u1ec1 thi\u1ebft b\u1ecb, ph\u1ea7n m\u1ec1m v\u00e0 k\u1ef9 thu\u1eadt. B\u1eb1ng c\u00e1ch tu\u00e2n theo c\u00e1c h\u01b0\u1edbng d\u1eabn tr\u00ean v\u00e0 l\u1ef1a ch\u1ecdn thi\u1ebft b\u1ecb ph\u00f9 h\u1ee3p, b\u1ea1n c\u00f3 th\u1ec3 ghi l\u1ea1i \u00e2m thanh si\u00eau \u00e2m m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3 v\u00e0 ch\u00ednh x\u00e1c, ph\u1ee5c v\u1ee5 cho m\u1ee5c \u0111\u00edch nghi\u00ean c\u1ee9u, ph\u00e2n t\u00edch v\u00e0 \u1ee9ng d\u1ee5ng trong nhi\u1ec1u l\u0129nh v\u1ef1c kh\u00e1c nhau.<\/p>\n","protected":false},"excerpt":{"rendered":"

\u00c2m thanh si\u00eau \u00e2m, v\u1edbi t\u1ea7n s\u1ed1 v\u01b0\u1ee3t qu\u00e1 ng\u01b0\u1ee1ng nghe c\u1ee7a con ng\u01b0\u1eddi, mang theo nhi\u1ec1u th\u00f4ng tin h\u1eefu \u00edch trong c\u00e1c l\u0129nh v\u1ef1c t\u1eeb y t\u1ebf, c\u00f4ng nghi\u1ec7p \u0111\u1ebfn nghi\u00ean c\u1ee9u khoa h\u1ecdc. Vi\u1ec7c ghi l\u1ea1i ch\u00ednh x\u00e1c \u00e2m thanh n\u00e0y \u0111\u00f2i h\u1ecfi thi\u1ebft b\u1ecb v\u00e0 k\u1ef9 thu\u1eadt chuy\u00ean bi\u1ec7t. B\u00e0i vi\u1ebft n\u00e0y<\/p>\n","protected":false},"author":1,"featured_media":26472,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6406],"tags":[],"class_list":["post-47260","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","prodpage-classic"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/posts\/47260","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/comments?post=47260"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/posts\/47260\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/media\/26472"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/media?parent=47260"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/categories?post=47260"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/tags?post=47260"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}