The Dictionary of Biblical Imagery has a thought-provoking summary of biblical teaching on silence.
Silence communicates. It is a basic feature of human relationships, for we must often interpret the silence of others. And by its very nature silence can express a wide variety of things. Usually it is not hard to interpret-the rebellious sullenness of a child, the hush as the school principal or head teacher enters. But sometimes silence is hard to interpret.
It is not surprising, therefore, that silence in the Bible expresses a wide range of emotions, attitudes and states: attentiveness, (Deut 27:9; Job 33:31; Acts 19:33) restraint, (1 Sam 10:27; Ps 50:12 Jer 4:19) respect and awe, (Job 29:21; Hab 2:20) loyalty, (Isa 36:21) deep thought, (Ac 15:12) acceptance of guilt, (Job 13:19; Rom 3:19) rest after tumult or suffering, (Ps 46:10; Mk 4:39) fear of saying something wrong, (Ps 39:2) even wisdom; (Job 13:5; Pr 17:28) more negatively, it can express faithlessness, (Es 4:14) fear, (Job 31:34; Acts 18:9) deep pain, (Job 2:13; La 2:10) rebellion, (Ps 32:2 Mk 3:4) defeat or destruction, (Ps 101:5; 143:12; Isa 47:5) and supremely death. (Ps 31:17-18; 94:17; 115:17) Significantly, there is one Hebrew verb (used, e.g., in Ps 18:40,101:5; La 3:53) that means both “to destroy” and “to keep silent.”
The biblical writers also occasionally exploit the “openness” of silence-for instance, Aaron’s silence in Le 10:3 (grief? rebellion? submission?), the silence of God, (Ps 44:23; 83:1) the silence of Jesus at his trial (Mk 14:61; cf. Isa 53:7) or the silence in heaven in Rev 8:1. Also worth mentioning here are significant absences of speech where we might expect something (for instance, from Nicodemus after Jn 3:21). In all these cases, we the readers have to supply the meaning of the silence, which acts as a metaphor or parable.