Allen, James P. (2020). Ancient Egyptian Phonology. Cambridge University Press. DOI:10.1017/9781108751827, p. 26. ISBN 9781108751827 "Most of the Demotic consonants have straightforward correspondents in Coptic and can therefore be presumed to have had the same values they do in Coptic."
Allen, James P. (2020). Ancient Egyptian Phonology. Cambridge University Press. DOI:10.1017/9781108751827, p. 28. ISBN 9781108751827 "The grapheme h̭ appears in words for which Coptic has /x̱/, such as h̭ꜥr "skin" > A ⳉⲁⲁⲣⲉ, B ϣⲁⲣ, F ϣⲉⲉⲗ, L ϣⲁⲣⲉ, M ϣⲉⲣ, S ϣⲁⲁⲣ."
Allen, James P. (2020). Ancient Egyptian Phonology. Cambridge University Press. DOI:10.1017/9781108751827, p. 76. ISBN 9781108751827 "Voice is not a phonemic feature of the consonantal system in any stage of the language."
Allen, James P. (2020). Ancient Egyptian Phonology. Cambridge University Press. DOI:10.1017/9781108751827, 74–75. ISBN 9781108751827 "The primary phonemic distinctions between the consonants in all stages of Egyptian are two, aspiration and palatalization...Aspiration remains a primary distinction throughout the history of the language."