I've mentioned my heavily pressured local lake, Freeman Lake, in the past, and as I continue to figure out the secrets of success there, I've been doing a lot of pondering. I noticed when I use braided line on my spinning rod, it makes a sound as the line goes through the guides, and as it has pressure on it when I'm reeling it in. So I surmise that the fish also hear this sound.
Further, I surmise, that though I cannot hear a sound, monofilament fishing line also makes a sound. I assume that fluorocarbon does as well. All making different sounds, and the sounds probably vary somewhat between brands/types/weights.
I've seen it said when fish are heavily pressured, that you should downsize your line and rig. I always thought of downsizing the line for the physical visibility of the line, but it just recently occurred to me, that the reduction in the sound of the line might be the true reason a smaller line is preferable.
What's everyone else think?