Lub ntsiab lus ntawm qhov hnyav ntawm lub suab ntsuas ntsuas (sound level meters)
Lub teeb liab suab nrov Ratio (SNR) yog qhov piv ntawm cov teeb liab muaj txiaj ntsig lub zog rau lub suab nrov tsis xav tau.
yog qhov piv ntawm cov teeb liab muaj txiaj ntsig rau lub suab nrov tsis xav tau. Nws feem ntau yog ntsuas hauv decibels. Txij li thaum lub hwj chim yog qhov ua haujlwm ntawm qhov tam sim no thiab qhov hluav taws xob, lub teeb liab-rau-suab nrov piv kuj tuaj yeem xam los ntawm tus nqi hluav taws xob, piv txwv li qhov piv ntawm lub teeb liab mus rau theem suab nrov, nrog rau cov qauv sib txawv me ntsis. Xam lub teeb liab-rau-nruab piv piv rau lub hwj chim: S/N=10 log Xam lub teeb liab-rau- suab nrov piv nyob rau hauv cov nqe lus ntawm voltage: S/N=10 log Vim lub teeb liab-rau- suab nrov piv thiab lub zog lossis qhov hluav taws xob yog logarithmic, txhawm rau txhim kho lub teeb liab-rau- suab nrov piv, nws yog ib qho tsim nyog yuav tsum tau ua kom muaj txiaj ntsig zoo thiab qhov sib piv ntawm tus nqi suab nrov, piv txwv li: thaum lub teeb liab-rau-suab nrov piv yog 100dB, qhov tso zis hluav taws xob yog 10,{16}} zaug lub suab nrov rau cov hluav taws xob hluav taws xob, qhov no tsis yog ib qho yooj yim.
Yog hais tias lub amplifier muaj SNR siab, nws txhais tau hais tias North View yog ntsiag to, thiab vim hais tias lub suab nrov qis, ntau cov ntsiab lus ntawm lub suab tsis muaj zog uas tau muab zais los ntawm lub suab nrov yuav raug nthuav tawm, ua rau muaj kev nce hauv suab nrov, muaj zog kev nkag siab ntawm huab cua, thiab nce nyob rau hauv lub dynamic ntau yam. Tsis muaj cov ntaub ntawv nruj los txiav txim seb lub teeb liab-rau-lub suab nrov piv ntawm lub amplifier yog qhov zoo lossis qhov phem, feem ntau hais lus, nws yog qhov zoo dua yog hais txog 85dB lossis ntau dua, thiab qis dua tus nqi longitude, nws tuaj yeem hnov cov suab nrov hauv lub suab paj nruag sib txawv nyob rau hauv tej lub suab nrov nrov. Ntxiv nrog rau qhov sib piv ntawm lub teeb liab-rau-nruab nrab, qhov ntsuas ntawm lub suab nrov ntawm lub suab nrov kuj tseem tuaj yeem siv rau hauv lub tswv yim ntawm cov suab nrov, uas yog qhov tseeb ntawm qhov ntsuas hluav taws xob los xam cov teeb liab-rau-suab nrov piv tus nqi, tab sis tus denominator yog ib qho ruaj khov. tus naj npawb: 0.775V, thaum tus lej yog lub suab nrov, yog li lub suab nrov thiab lub teeb liab-rau-nruab nrab ntawm qhov sib piv: tus lej qub, tus lej tom kawg yog tus lej txheeb ze.
Nyob rau hauv cov khoom siv phau ntawv nyob rau hauv cov lus qhia tshwj xeeb tom qab cov ntaub ntawv, feem ntau yuav muaj ib lo lus A, lub ntsiab lus A-qhov hnyav, uas yog, qhov hnyav, qhov hnyav txhais tau hais tias ib qho nqi raws li qee txoj cai hnyav qhov tseem ceeb ntawm kev hloov kho, vim hais tias cov tib neeg pob ntseg tsis hnov tsw rau nruab nrab zaus, yog li yog tias lub amplifier nyob rau hauv nruab nrab-frequency band teeb liab-rau-suab nrov piv yog loj txaus ces, txawm tias lub teeb liab-rau-suab nrov yog qis dua qhov tsawg-frequency thiab siab- zaus bands, tib neeg pob ntseg tsis yooj yim mus ntes. Nws tuaj yeem pom tau tias yog qhov ntsuas-rau-lub suab sib piv ntsuas nrog qhov hnyav, tus nqi yuav siab dua yam tsis muaj qhov hnyav. Nyob rau hauv cov ntaub ntawv ntawm A-hnyav, tus nqi yog siab dua tsis muaj qhov hnyav.
Tsis tas li ntawd, txhawm rau simulate qhov rhiab heev ntawm tib neeg pob ntseg ntawm ntau zaus, muaj lub network nyob rau hauv lub suab ntsuas ntsuas uas tuaj yeem simulate cov yam ntxwv ntawm tib neeg pob ntseg, kho cov teeb liab hluav taws xob rau qhov kwv yees tus nqi ntawm kev hnov lus, uas yog hu ua qhov hnyav network. Lub suab siab ntsuas ntsuas los ntawm qhov hnyav network tsis yog lub hom phiaj lub suab lub suab siab theem (hu ua linear sound pressure level), tab sis lub suab siab kho los ntawm kev hnov lus, hu ua qhov hnyav suab los yog suab nrov.
Feem ntau muaj peb hom kev tes hauj lwm hnyav, A, B thiab C. A-hnyav suab qib yog simulate cov yam ntxwv zaus ntawm cov suab nrov qis qis qis dua 55dB rau tib neeg pob ntseg, B-weighted suab theem yog simulate zaus cov yam ntxwv ntawm nruab nrab. Kev siv lub suab nrov ntawm 55dB txog 85dB, thiab C-weighted suab yog simulate tus yam ntxwv zaus ntawm kev siv suab nrov. Qhov sib txawv tseem ceeb ntawm peb yog qib ntawm attenuation ntawm cov suab nrov qis, nrog A attenuating tshaj plaws, B qhov thib ob, thiab C tsawg tshaj plaws. A-weighted suab theem tam sim no yog siv dav tshaj plaws nyob rau hauv lub ntiaj teb no lub suab ntsuas vim nws cov yam ntxwv nkhaus nyob ze rau tib neeg pob ntseg auditory zog, thaum B thiab C tau maj mam tshem tawm.
