When you hear a nice southern accent, especially from a female speaker, you hear that twang. When men speak, I suppose it’s more of a drawl.
Twang is considered an onomatopoeia.
That Twang is an onomatopoeia might seem straightforward enough. But upon further reflection, it became a much more fraught topic. Twang is characterized as an onomatopoeia based on the second definition, which is the sound like when a banjo string is plucked: the sound is similar to the word, or perhaps the word is divined in the reverberation of that quaint instrument. Put another way, the word is a literal representation of the sound.
But to hear the twang of a woman speaking in a southern accent, one can hear the word twang in there, although implicitly, in those plucky, sassy tones that such women make with their delightful regional accents.