he should searching for not only a place where the sound is not an issue, he should find for a place where the temperature is not an issue too, dont forget that

btw about to reduce the noise, there is one thread talking about how to underclock the s5 here -> https://bitcointalk.org/index.php?topic=1151460.0  i know is not what are you searching for, but maybe reduce it a little bit will bring you a reduction of the noise, dunno.