Carthusian monks are a silent order apart from their singing of the liturgy.
From the gazetteherald.co.uk
Carthusian nuns live a life similar to the monks, but with some differences.
From the en.wikipedia.org
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Of or relating to the Carthusian order
A monastic order founded in Chartreuse, in France, in the 11th century; a contemplative order whose brethren were bound to vows of silence and renunciation of the world
A late medieval order of clergy with an emphasis on learning, contemplation and solitude