This study explores silence in a corpus of university supervisors’ (USs) utterances in the context of post-observation feedback conferences (POFCs) with their Teaching English to Speakers of Other Languages (TESOL) supervisees. The USs’ utterances and corre­sponding silences were divided into educative, supportive and evaluative conversational frames (Long et al. 2013), with a view to discovering the extent and nature of the silent spells within these frames. It appears that silent spells within the educative frame type were a powerful means of communication comparable to reflection hubs, which could be allocated to increased “wait time” (Rowe 1972) or “slow-time” (Bruneau 1973) and could also be considered examples of social or commission silences. The agential quali­ties of this silence, though, can in certain cases be disempowered due to a tutee’s close-mindedness towards what happened during their lessons. Conversely, silent moments in the evaluative frame served to recall the observed lessons and included examples of empirical silence or omissive silence that the USs failed to use. This ethnographic research on USs’ silence is an extension of previous studies on USs’ POFCs discourse, and the self-analysis is a self-awareness-raising-tool in order that USs may become more cognizant of the ways POFCs are managed.