This noise may refer either to the waters, the sounding rivers (nads, nads), or the lowing cows (gavas).
gonads; testicles, esp. in the sense of having courage
He may not have the nads to go to the coach and ask for help.
The male gonads; testicles; balls, family jewels: Apparently I was no longer rousing his 'nads/ When we found him his nads were gone
[1980s+; nard, ''testicle,'' is found in 1960s student slang and is probably also a shortening of gonad]