What is a Plunger Mute?

A plunger mute is a brass playing device used mainly with trumpets and trombones, consisting of a rubber cup—often similar to the head of a household sink plunger—that is held in front of the instrument’s bell to modify the sound.

Instead of being inserted into the bell like many other mutes, the plunger mute is manually moved closer to or farther from the bell while the player performs. This movement changes the shape and direction of the sound waves, producing expressive effects such as the well-known “wah-wah” sound.

Plunger mutes are commonly used in jazz, big band music, and certain orchestral passages to create playful, vocal-like effects. Trombone and trumpet players often combine plunger techniques with articulation and pitch bending to imitate speech-like sounds or dramatic musical gestures.