> Sure, if you stop after "nobody's vocal coords make noises above 4khz in normal conversation"
Huh? What? That's not even remotely true.
If you read your comment out loud, the very first sound you'd make would have almost all of its energy concentrated between 4 and 10 kHz.
Human vocal cords constantly hit up to around 10 kHz, though auditory distinctiveness is more concentrated below 4 kHz. It is unevenly distributed though, with sounds like <s> and <sh> being (infamously) severely degraded by a 4 kHz cut-off.
Huh? What? That's not even remotely true.
If you read your comment out loud, the very first sound you'd make would have almost all of its energy concentrated between 4 and 10 kHz.
Human vocal cords constantly hit up to around 10 kHz, though auditory distinctiveness is more concentrated below 4 kHz. It is unevenly distributed though, with sounds like <s> and <sh> being (infamously) severely degraded by a 4 kHz cut-off.