noun. ib lub raj rau xa lub suab hla qhov deb me ntsis, raws li ib feem ntawm lub tsev lossis nkoj mus rau lwm qhov.
Tube tham yog dab tsi?
Ib lub raj hais lus, tseem hu ua megaphone lossis lub suab raj yogyooj yim, luv luv ntau yam khoom siv lub suab kis tau tus mob, muaj cov raj hlau lossis cov yeeb nkab ncab los ntawm ib qho chaw ruaj khov rau Lwm qhov, feem ntau nrog lub horn zoo li apertures ntawm ob qho kawg.
Cov raj hais lus ua haujlwm li cas?
Hauv tsev, lawv raug hu ua " hais lus ." Thawj qhov tsim tawm ntawm lub suab pipe muaj ob lub khob ntoo lossis hlau, ib qho kawg zoo li tus neeg hais lus lub qhov ncauj, txuas nrog rau lwm qhov uas ua rau lub suab nrov. … Dalnavert's speaking tube txuas chav ua noj rau Lady MacDonald's chav dej.
Leej twg tsim lub raj hais lus?
Tus kws tshawb fawb Askiv tus kws tshaj lij Jeremy Benthamtau thov kom suav nrog "kev sib tham" hauv kev tsim vaj tsev ntawm nws Panopticon (1787, 1791, 1811) thiab tom qab ntawd raws li kev sib txuas lus tub rog (1793) thiab thaum kawg raws li cov cuab yeej tsim nyog hauv architecture ntawm Ministry (1825).
Lub raj hais lus tau tsim thaum twg?
Cov raj hais lus hnub rov qab mus rau ncig 1849, thaum ib tsab xov xwm hauv Scientific American tau piav txog "acoustic telegraph" uas yuav ua rau tib neeg sib tham nrog phooj ywg "txog debraws li 60 mais deb" (!) ntawm lub raj ua los ntawm gutta percha (ib cov khoom latex tau los ntawm cov ntoo nyob rau sab hnub tuaj Asia).