Table 1.

Definitions of speechlessness depending on scientific discipline

Scientific discipline	Name	Definition	References
Neuro-biological	Aphasia	Disorder of language comprehension and development caused by cognitive dysfunction or trauma	(Damasio, 1992)
Psychopathological	(Selective) Mutism	Partial or complete absence of speech in specific situations (e.g., school), although a normal speech ability is presented/unrestricted	(Muris et al., 2021)
	Speechless Terror	Traumatic memories that occur throughout life and, due to cognitive processes during the traumatic experience, cannot be completely realized and accurately described later in life.	(Harris, 2009; van der Kolk, 1987; van der Kolk et al., 1996; van der Kolk & van der Hart, 1991)
Psychosomatic	Alexithymia	Dysfunction in the perception, identification and (verbal) expression of emotions.	(Bagby & Taylor, 2020; Preece et al., 2017; Taylor, 2000)
Psychological	Speechlessness	Non-strategic or strategic non-speaking that lasts beyond the duration of a normal pause in speech and impedes communication between interlocutors	(Berger, 2004)
	Silence	Different forms of silence depending on contextual factors; primarly types of speechlessness to be adressed: (1) psychological silence can be attributed to an unconscious and physiological processes; (2) sociocultural silence forms a latent social factor that leads to silence (3) interactive silence is an interactive, conscious process during conversation	(Bruneau, 1973)
		(1) conversational silence often occurs in dyadic interaction and can be considered as equivalent to the act of speech (2) thematic silence ccours in a conversational context where the individual does not say something regarding a specific subject (3) textual silence refers to a specific context, where an individual reads in silence (e.g. library or at home) (4) situational silence occurs in situations, where larger groups of people do not speak relating to situation or context (e.g. church or memorial)	(Kurzon, 2007)
	alexinomia	Inability to pronounce a person’s personal name in social interactions and/or interpersonal relationships between multiple people.	(Ditye et al., 2023)