An R word that transmits sound is a radio.
None of them technically start with r, since the Japanese writing system uses sounds, not words. So they would start with ra, ru, re, ri, ro, rya, ryu, or ryo, but not r.
Telephone
Yes. The A has a short A sound as in tram or cans.
transmit transmission transcend transatlantic
tympanic
Yes, here is a tongue twister that starts with the letter "R": "Red lorry, yellow lorry." It is challenging to say quickly due to the repetition of the "r" and "l" sounds.
The word "rough" has 5 sounds: /r/ /ʌ/ /f/. /r/ /ə/ /f/.
cd r is used for recording sounds and video
Words that start with R and end with R:racerradarradiatorrafterrancherrancorratherrazorreaderreaperreappearrearreceiverrecorderrecoverregisterregularregulatorreindeerrelieverremainderrememberreminderremoverrenterreoccurrepairreporterresistorresponderretailerretainerretrieverrevolverriderrigorringerriserriverroarrobberrockerrollerrooferroosterrosterrubberrulerrumorrunner
A wire would transmit sounds better than air because it is a solid medium that allows sound waves to travel more efficiently and with less loss of energy. Air, being a gas, is less dense and can absorb and scatter the sound waves, leading to weaker transmission.
With a vibration.
The word "ruse" is pronounced as rooz. The 'r' sounds like the letter 'r', and the 'u' sounds like the 'oo' in "boot."