This isn't a description of Broadbent's early selection theory. This card more accurately describes the use of sensory registry. All of the theories of attention include the sensory registry as the first step.

Broadbent's early selection theory in specific is the idea that after information reaches the sensory registry, some of it is selectively filtered out.

There might be better ways to word the revision I suggested.

Source: https://www.khanacademy.org/science/health-and-medicine/executive-systems-of-the-brain/attention-language-lesson/v/selective-attention