Just in case you are not familiar with the terminology, pulmonic ingressive sounds are made with air drawn into the lungs rather than the usual outward direction of pulmonic egressive sounds. When I was teaching phonetics and dealing with the matter of airstream mechanisms I regularly skimmed over the matter of pulmonic ingressive sounds. This was just to keep things simple. Pulmonic ingressive sounds are quite interesting, however.
Usually published accounts of airstream mechanisms do what I used to do and say airily that they are only used for paralinguistic purposes like expressing pain. There is more to the matter than that.
First, there is the matter of Damin, a ritual language spoken by members of two Australian peoples, the Lardil and the Yangkaal, who live on islands in the Gulf of Carpentaria. It seems likely that the language was invented by the Lardil, though they maintain that it was created by a mythological figure in the Dreamtime. The phoneme inventory of Damin is very similar to that of Lardil, except that it contains six extra consonant segments:
- Four nasalised clicks: ŋʘ ŋ| ŋǃ ŋǂ (Damin is the only language outside Southern Africa to have clicks)
- A reverse click kʘ↑
- A pulmonic ingressive voiceless lateral fricative ɬ↓
Next we have ǃXóõ, a language of Botswana, which has a stupendous array of clicks, including aspirated clicks with a voiceless ingressive nasal accompaniment at five places of articulation – ↓ŋ̊ʘʰ and the like. You can hear sound files for these and all the clicks at the UCLA Archive.
Then there is the mysterious case of Tsou, a Taiwanese language. Sometime in the 1990s a study of the speech of one speaker of this language was published in the Journal of the International Phonetic Association. It was reported that word-initial voiceless fricatives were produced with a pulmonic ingressive airstream mechanism. A subsequent study with other speakers failed to corroborate this finding.
I think the use of pulmonic ingressive speech as a paralinguistic feature is rather under-researched. However, there is some interesting information about this on Robert Eklund’s site.