<P> Among the symbols of the IPA, 107 letters represent consonants and vowels, 31 diacritics are used to modify these, and 19 additional signs indicate suprasegmental qualities such as length, tone, stress, and intonation . These are organized into a chart; the chart displayed here is the official chart as posted at the website of the IPA . </P> <P> The letters chosen for the IPA are meant to harmonize with the Latin alphabet . For this reason, most letters are either Latin or Greek, or modifications thereof . Some letters are neither: for example, the letter denoting the glottal stop, ⟨ ʔ ⟩, has the form of a dotless question mark, and derives originally from an apostrophe . A few letters, such as that of the voiced pharyngeal fricative, ⟨ ʕ ⟩, were inspired by other writing systems (in this case, the Arabic letter ع ‎' ain). </P> <P> Despite its preference for harmonizing with the Latin script, the International Phonetic Association has occasionally admitted other letters . For example, before 1989, the IPA letters for click consonants were ⟨ ʘ ⟩, ⟨ ʇ ⟩, ⟨ ʗ ⟩, and ⟨ ʖ ⟩, all of which were derived either from existing IPA letters, or from Latin and Greek letters . However, except for ⟨ ʘ ⟩, none of these letters were widely used among Khoisanists or Bantuists, and as a result they were replaced by the more widespread symbols ⟨ ʘ ⟩, ⟨ ǀ ⟩, ⟨ ǃ ⟩, ⟨ ǂ ⟩, and ⟨ ǁ ⟩ at the IPA Kiel Convention in 1989 . </P> <P> Although the IPA diacritics are fully featural, there is little systemicity in the letter forms . A retroflex articulation is consistently indicated with a right - swinging tail, as in ⟨ ɖ ʂ ɳ ⟩, and implosion by a top hook, ⟨ ɓ ɗ ɠ ⟩, but other pseudo-featural elements are due to haphazard derivation and coincidence . For example, all nasal consonants but uvular ⟨ ɴ ⟩ are based on the form ⟨ n ⟩: ⟨ m ɱ n ɳ ɲ ŋ ⟩ . However, the similarity between ⟨ m ⟩ and ⟨ n ⟩ is a historical accident; ⟨ ɲ ⟩ and ⟨ ŋ ⟩ are derived from ligatures of gn and ng, and ⟨ ɱ ⟩ is an ad hoc imitation of ⟨ ŋ ⟩ . </P>

What is the name of the system actors use to transcribe the sounds of speech