Perhaps the animals they hunted, or feared, produced sounds in the range above 10kHz.
On 2011, Feb 4, at 6:18 PM, Piotr Majdak wrote:
Nice shots, Kevin. What's the upper frequency limit of those apes? For
chimpanzees it is approx. 30 kHz...
Kevin Austin wrote:
I may be prejudiced [specious bias], but I think these ears have greater prominence than mine.