Final answer:
An assembly of hearers at a conference or concert can be referred to as a crowd.
Step-by-step explanation:
An assembly of hearers at a conference or concert can be referred to as a crowd. A crowd is a large group of people who gather together in a spontaneous activity that lasts a limited amount of time. Examples of crowds include attendees at a concert, a sporting event, or a worship service. Crowds can have different types, such as casual crowds, conventional crowds, expressive crowds, and acting crowds.