Listen to the sounds in the room. And notice how each one articulates the space of consciousness.
Sam Harris often uses this expression, or similar ones: sense impressions "articulate" the space of consciousness (awareness). They "modify" it. They "pertubate" it.
In other meditations, this statement includes not only hearing but also all other sense impressions defined by Buddhist psychology:
All of these, as they arise, "articulate" or give form to consciousness.
Please note that in Buddhist psychology, the mind itself is also considered to be a sense system. Thus, thoughts have the same status as sights, sounds, etc. The only difference is that the mind also acts as an integrator (this is well explained by Culadasa, in his analogy of the mind being a share working workspace for all senses). Thus, thoughts too "articulate the space of consciousness".
Daniel P Brown (extended quote)
Daniel P Brown uses a different term for what Sam Harris calls "articulation": he uses the expression "the mind takes the shape" of the sense impressions, and he uses an analogy to the mirror metaphor. In analogy, a mirror surface "takes the shape" of the reflected objects in the moment of reflection.
The following quote is taken from the chapter on concentration meditation. It shows how complex the underlying Buddhist tradition is. it is meant as teaser to dive more deeply.
The intended object can come from any of the six senses—a sight, sound, smell, taste, touch sensation, or thought. Since a common approach to concentration training is to use a visual object, the term could also be translated as “visualization.” For each of the six sense systems described in Buddhist psychology the mind is said to take the shape of or reflect the qualities of its intended object as if it were a reflected image in a mirror (snang brnyan; Skt., pratibimbakam). The term attribute (mtshan ma; Skt., nimitta) is often used in conjunction with the technical term representation. Attribute refers to various (sna tshogs) qualities of sensory experience. The act of making a representation during concentration meditation is a process by which the mind continuously holds (’dzin pa) the sensory attributes of the intended object in awareness. As the attributes of each intended meditation object are unique, the mind particularizes only these attributes during concentration, and is not distracted by other events in the mental continuum. This is called taking-to-mind, or mentally engaging (yid la byed pa), the intended object. The term literally means “doing something in the mind” because concentration requires continuous, effortful mental activity to hold the attributes of the intended object over and against everything else that is and will occur in the unfolding mental continuum. “Taking-to-mind” is an extremely important concept, because during the advanced, extraordinary practices in the mahāmudrā tradition the practitioner is given an instruction that is exactly opposite to that of the earlier concentration practices. That is to say, these extraordinary realizations occur only through not-taking-to-mind, through not doing anything to meditate. More will be said about this later. (D. P. Brown & Thurman, 2006, p 224)
Brown, D. P., & Thurman, R. (2006). Pointing Out the Great Way: The Stages of Meditation in the Mahamudra Tradition (Annotated). Wisdom Publications.
Yates (Culadasa), J., & Immergut, M. (2017). The Mind Illuminated: A Complete Meditation Guide Integrating Buddhist Wisdom and Brain Science for Greater Mindfulness. Hay House Uk.