Click consonants
A click is produced with two oral closures and a rarefied pocket of air between them. Releasing the forward closure gives the characteristic sound. The IPA has distinct basic symbols for bilabial [ʘ], dental [ǀ], (post)alveolar [ǃ], palatoalveolar [ǂ], and lateral [ǁ] clicks. A language-specific transcription also needs to indicate accompaniments such as nasalization, voicing, or aspiration when relevant. The basic symbol alone does not encode every contrast.
Clicks can be ordinary consonants that distinguish words in a language. WALS separates such lexical use from paralinguistic clicks such as a conventional expression of disapproval. A phonetic study of Hadza records acoustic and aerodynamic properties of its click types and accompaniments. An unfamiliar sound should therefore be analyzed by articulation, contrast, and distribution, not by imitation or by a claim that it is beyond normal speech.
A whistled mode
Whistled speech transposes an ordinary spoken language into a whistle signal. It can carry words and sentences, but its acoustic channel is much narrower than ordinary speech. Meyer’s review shows that the mapping varies with the phonology of the source language: pitch patterns can be especially important in tonal languages, while whistled versions of nontonal languages can use frequency differences to convey vowel and consonant information. Context also helps listeners recover a message.
Silbo Gomero is a documented whistled mode of Spanish on La Gomera. UNESCO records its teaching and community use. Its conventions should be explained in relation to Spanish, not generalized into a universal whistle alphabet. A whistled mode and a click phoneme differ in scale: the former re-encodes an utterance; the latter can fill a consonant position inside an ordinary word.
Limits of written evidence
An alphabetic sign, pictograph, or unusual transliteration mark is not evidence by itself for a click or a whistle. Click identification requires a linguistic reading or phonetic description; whistled traditions require acoustic and social evidence. An ancient text without those sources cannot reveal a lost whistled mode merely because the environment would have favored long-distance communication.
Practice: for a documented click, list place, accompaniment, phonemic status, and cited form. For a whistled variety, identify the spoken language and which contrasts the whistle conveys. Keep sound mechanism, linguistic function, and community practice in separate notes.
Modern-language examples on this page clarify a linguistic pattern. They do not establish unattested sounds or forms for an ancient language. Follow the cited sources below and keep editorial readings separate from the surviving trace.