ðə dˈɪfɹəns bᵻtwˌiːn ðə tˈuː ɪz ðə ɹɪzˈʌlt ʌv sˌaɪkoʊɐkˈuːstɪks, mˈoːɹ spəsˈɪfɪkli ðə fˈækt ðætðə hjˈuːmən hˈɪɹɪŋ ɪz mˈoːɹ sˈɛnsᵻtˌɪv tə sˌʌm fɹˈiːkwənsiz ðɐn ˈʌðɚz.
The difference between the two is the result of psychoacoustics, more specifically the fact that the human hearing is more sensitive to some frequencies than others.