To Rattle Or Not To Rattle, Different Tones Of The Rattle???

Being with the engineering group testing for over 20+ years I get into everything and ask why...

Then i read about a low pitch rattle and a high pitch rattle in lures.

Examples;

The low pitch would be a single ball knocker in a spook or topnocker it gives off a single lower tone rattle.

The higher pitch would be the smaller multiple ball rattle in a bomber crankbait, its a finer tone sound.

The single ball low pitch knocker seems to call fish in from a farther distance away. The finer high pitch rattle seems to work in that general area close to where your fishing. But at the sametime both rattles seem to work very well and pretty much equal.

Any thoughts????