Hello, old thread!
NANGI said:
"rainy sound" is 雨音(amaoto).
This is a very old thread, but I wonder if the following is a workable analogy.
Three ways to string two nouns together; noun#1 = 雨, noun#2 = 音.
1. (adjectival construction of noun#1)-noun#2
雨の音 ame no oto: English using preposition 'of' to connect two nouns as in
'sound of rain'
2. (noun#1 functioning as a limiting modifier)-noun#2
雨音 amaoto: English has no problem with stringing plain nouns together.
'rain sound', e.g. rain dance, rain man, rain check, rain coat
3. (noun#1 functioning as subject of a paticipial clause)-noun#2
雨の降る音 ame no furu oto
'rain-falling sound'
As for the actual sound of rain, it could be rain drops hitting the ground, the road, the grass, pools of water, rooftops, windows, or the sounds of flowing water down the spout, stream, or the sounds of wind associated with monsoon rain. Forms 1. 2. and 3. in a sentence or paragraph each can evoke different sound images by distancing itself from the normal usage. I do not know Japanese to say anything in particular, but it seems to work in other languages I know.