As a voice enhancer, this tool focuses on speech intelligibility rather than musical tone — the mid and high-mid range this equalizer controls directly.
A gentle boost around 2.5kHz tends to help words cut through background noise or music. Cutting a little around 500Hz can reduce a muddy, closed-in quality that makes speech harder to follow, especially in phone or laptop-mic recordings.
Over-enhancing a voice recording — pushing the high-mid band too far — tends to introduce a thin, processed quality rather than genuine clarity. A voice that sounds natural but slightly clearer is usually a better result than one that sounds obviously EQ'd.