The sacred writing of Egyptian king Tutankhamun's throne name is shown belong aside the same name as it appears in a letter written in cuneiform to his majesty from the king of the Hittites.
The four signs in the Egyptian form (reading from the bottom) can be transliterated as Nb-U-Kheper-Ra. Therefore, we might expect the name to be pronounced "Nibukhepera." (Note that Nb should be Nib, not Neb, because Neb meaning gold is a different sign. Nib means 'everything'.)
The cuneiform beside it is transliterated by Guterbock as Ni-ip-khu-ru-ri-ia-as, which seems to be somewhat different than the Egyptian. For example, if we take the Hittite to be Nip-Khuru-Ria-as, the -as being a personal suffix, then Kheper becomes Khuru and Ra becomes Ria and U is silent. This is strange because the P in kheper has become an R in Hittite, which seems unlikely because a rhotic consonant is being transmuted to a plosive.
On the other hand, if we take the Hittite to be Nip-Khu-Ruri-Ia-as, then Khu and Ra/Ya closely match, but Kheper is Ruri, where once again we have a severe change of sounds.
The bottom line here seems to be that the Hittites are not pronouncing the scarab as Kheper, but are pronouncing some other way. So, does this point to the traditional pronounciation of the scarab being either incorrect, or incorrect in the New Kingdom period of time, perhaps?