About the behavior of the larynx and glottis in the production of consonants

Question

Consider the following three consonant sounds in intervocalic positions: a dental click, an (aspirated) voiceless alveolar stop, and a palatal nasal. I'm trying to understand what happens with (1) glottis (how the openness of the glottis changes), (2) larynx (how the degree of raising of the larynx changes), (3) pressure in vocal tract relative to outside (how the pressure changes) as one pronounces [aǀa], [atʰa], [aɲa].

Here are some of my hypotheses:

(1) In all three cases, when the consonant is produced, the glottis closes, and when the vowels surrounding the consonants are produced, the glottis is open. Is this right?

(2) I don't have any intuition on what happens with the larynx in these cases. I know that for ejectives, the larynx is raised, and for implosives, the larynx is lowered. But what happens for clicks, oral stops, and nasals?

(3) I suppose, in the case of [aǀa] and [atʰa], the air pressure becomes higher when we pronounce [|] and [tʰ] (compared to the pressure when [a]s are pronounced). In the case of [aɲa], I suppose the pressure is uniform across the three segments. Is that right?

Answer 1

In none of [aǀa], [atʰa], [aɲa] does the glottis close. In the case of an ejective stop, the glottis closes, and there are "glottalic clicks", sometimes transcribed as e.g. [aǀ'a]. Larynx lowering sometimes accompanies voiced stops, but this isn't a general feature of clicks, aspirated stops or nasals.

When you ask about air pressure, I assume you mean intraoral air pressure (behind the constriction). Your supposition about no increase in air pressure is theoretically correct, though actual measurements show minor artifacts during the nasal (a small, temporary increase at the oral-to-nasal boundary and periodic increases owing to glottal pulses). If you smooth the signal, you'll get a non-zero but negligible pressure difference compared to e.g. [aza].