Weird sounds during rainy day in-game?

[Milky-san]

So, basically, I recently started to play HM:SI for the first time in life, but I noticed something weird.
Whenever there is a rainy day and the rain sounds are playing rather than the usual music, there are strange little sounds in the underlying tones of the "music"; totally not rainy day sounds at all.
Nothing horribly noticeable, but definitely irksome.
I was just wondering if this was a common trend in all the copies of the games, rather than it just being a special, um...feature in mine.
Thank you for any and all input!

[Shan O 123]

Um, I haven't played SI in years, but when it rains there's usually no music playing, just the sound of the rain falling.

[Milky-san]

Yeah, but...Under those rainy sounds, there are odd sounds.
It's difficult to explain; it's a lot more noticeable w/ headphones.

[Shan O 123]

I didn't use headphones however that is odd. I never noticed it myself sorry.