I have to do another post on this. http://asa.scitation.org/doi/abs/10.1121/1.1974668 http://asa.scitation.org/doi/abs/10.1121/1.1974668 This has been a pet th

I have to do another post on this. http://asa.scitation.org/doi/abs/10.1121/1.1974668 http://asa.scitation.org/doi/abs/10.1121/1.1974668 This has been a pet theory of mine monkeys hearing is not very good below 8khz, down as much as 60db in the 4khz and below range where human speech primarily resides. Maybe they are basically hard of hearing in our spectral range? I wonder if anyone ever thought about making a special hearing aid for them to boost the low frequencies. Or maybe move the human speech up to their range (they can hears as high as 45Khz while humans cut off at 20khz). Maybe you could teach them to speak but it would be super high pitched and another device could shift it back down. Like a frequency up and down converter.