A traditional classroom where all learners hear a lecture at the same time is known as:

The definition of a traditional classroom setting where all learners are engaged in the same instructional activity at the same time aligns perfectly with synchronous learning. In this environment, instruction happens in real-time, allowing for immediate interaction between the instructor and students. This format is characterized by a shared schedule, where learners participate simultaneously in activities such as lectures or discussions, facilitating a cohesive learning experience.

Asynchronous learning refers to a format where participants engage with the material at different times, allowing flexibility but lacking simultaneous interactions. Hybrid learning combines elements of both online and in-person engagement, providing a blend of synchronous and asynchronous experiences. Simultaneous learning could imply different contexts but is not the widely accepted term for the traditional classroom scenario described, making it less suitable here. Hence, the identification of this setting as synchronous learning accurately captures the nature of the classroom dynamic.