A dynamic whereby people who disagree with opinions in the mass media are less likely to voice their views.

spiral of silence

Explanation:

The term "spiral of silence" was coined by the German philosopher and politician Elisabeth Noelle-Neumann, to explain why people remain, in many cases, silent when they often have the false sense that their opinions and philosophies, worldview, worldview, or their general idea of the organization of the cosmos according to scientific discoveries or even their set of intuitions are in the minority.

The theory began to be studied in the 1960s, based on research into the effects of mass media on the population.

In short, we can say that the spiral of silence is the dynamic by which people who disagree with mass media opinions are less likely to express their opinions.

Your answer should be spiral of silence!