This is the 16789th most frequent Russian word.
слушателей
"Listeners" or "audience."
In this sentence, 'слушателей' is in the genitive plural form and refers to the audience attending a lecture or presentation.
Лектор отметил высокий уровень подготовки своих слушателей.
The lecturer noted the high level of preparation of his audience.
Here, 'слушателями' is in the instrumental plural form and describes the students in the role of listeners who actively participated in the seminar.
Студенты стали активными слушателями на семинаре.
The students became active listeners at the seminar.
In this usage, 'слушателей' is in the accusative plural form, indicating people who have come to listen to an event or presentation.