What is tenseness with respect to consonants?

Question

In korean, consonants are divided into three categories of articulation or coarticulation, one of them is called Tenseness.

In korean orthography, tensed consonants are written with a reduplicated consonant sign. In IPA orthography, they are written with a pair of vertical parallel lines at the bottom of the letter:

P”ㅃ T”ㄸ Tɕ” ㅉ K” ㄲ

There is an article on Tenseness in Wikipedia, but it is on the Tenseness of vowels, nethertheless it is describing the articulatory way of production well: widened mouth, less open, uplift tongue.

How about the Tenseness of consonants, what exactly is happening inside the the mouth and beyond, what is happening in the articulatory system in order to create them?

Answer 1

This article starts with a convenient summary of the literature on the production of Korean tense consonants. One of the first studies on the topic is C.W. Kim "On the autonomy of the tensity feature in stop classification" (Word 1970), who found they they involve greater duration of oral pressure buildup, less airflow at the start of the vowel and greater EMG activity (in the lips, for labials); there is also a significant lag in voicing at release. Various other studies have indicated significant laryngeal involvement in the production of the tense consonants, so that they could be called "glottally constricted" without being ejective. Additionally, they are longer to the point that there are two phonological analyses, one where they are treated as geminate consonants, and one where they are single consonants with a glottal feature.