Final answer:
After focusing on a sound in the listening process, the next step is to assign meaning to interpret the message. This involves understanding the communication's content and context.
Step-by-step explanation:
In the context of the five steps of the listening process, once you have chosen a sound to focus on, the next step you must do is assign meaning. This involves interpreting and understanding the message that is being communicated. The correct option after choosing a sound to focus on is a. assign meaning. The other options listed, such as make an effort to attend, provide feedback, and stop listening, correspond to other stages within the listening process, but to assign meaning is the immediate step after focusing on a sound to fully grasp the content and context of the communication.