Question

how sound travel through one end of a thread to other

Answer 1

sound travels through a thread in a longitudinal wave .........the energy pushes the 1st particle and the 1st particle exerts force on the 2nd particle to move on by creating a region of low pressure and high pressure which we know as rarefaction and compression.and that's how a sound energy travels through a thread .

i hope it helps................  

Answer 2

actually what happens is.....sound waves via vibrations pass through the threads's end A to end B.!! as the sound vibrations strikes a human ear at the end B..those are converted as messages for our brain and we get to know what the person at end A is reciting .!! sound vibrations transmits in the thread so hence , we get to hear sound in end B when a person speak something at end A ....
Hope it helps.!
PT.