See the video linked in the sister comment for (IIRC) an excellent discussion of historical reconstruction of sounds from writing systems, but I can add some cl

See the video linked in the sister comment for (IIRC) an excellent discussion of historical reconstruction of sounds from writing systems, but I can add some clarification to the matter of laryngeal consonants: they are confusingly named for historical reasons but consitute three unknown consonants with a place of articulation towards the back of the vocal tract (near the larynx). In addition to this reconstruction, this specific case has the additional matter of finding consonants in a place where they are predicted from their influence on the nearby vowels in IE languages (and, incidentally, the expected vowels), but where there is otherwise no consonant attested in non-Anatolian IE languages.