U+10780 Modifier Letter Small Capital Aa

The Wikipedia has the following information about this codepoint:

Voice Quality Symbols (VoQS) are a set of phonetic symbols used to transcribe disordered speech for what in speech pathology is known as "voice quality". This phrase is usually synonymous with phonation in phonetics, but in speech pathology encompasses secondary articulation as well.

VoQS symbols are normally combined with curly braces that span a section of speech, just as with prosody notation in the extended IPA (extIPA). In fact, they started off as part of extIPA before being split off. The symbols may be modified with a digit to convey relative degree of the quality. For example, ⟨V!⟩ is used for harsh voice, and {3V! ... 3V!} indicates that the intervening speech is very harsh. ⟨L̞⟩ indicates a lowered larynx. Thus, {L̞1V! ... 1V!L̞} indicates that the intervening speech is less harsh with a lowered larynx.

VoQS use mostly IPA or extended IPA diacritics on capital letters for the element being modified: V for 'voice'/articulation, L for 'larynx', and J for 'jaw'. Degree is marked 1 for slight, 2 for moderate, and 3 for extreme.