What type of clause is shown in parentheses the students listened whenever intercom buzzed?

The clause in parentheses "(the students listened)" is an adjective clause.

Here's why:

* It modifies a noun: The clause describes the students, the noun in the main clause "whenever the intercom buzzed."

* It functions as an adjective: It acts like an adjective, providing more information about the noun it modifies.

* It includes a subject and verb: The clause has the subject "students" and the verb "listened."

Therefore, the clause in parentheses is an adjective clause, specifically a restrictive adjective clause because it is essential to understanding which students are being referred to.