Walla
Definition
Background voices or crowd ambience used in film and television post-production to create the sense of people in an environment — a restaurant, a crowd, a busy office. Walla is typically non-intelligible to avoid competing with foreground dialogue.
In Simple Terms
Background crowd noise used in film and TV — the murmur of a restaurant, the chatter of a busy street. It's intentionally vague and blurry so it feels real without any words competing with the actual dialogue.
In Practice
A coffee shop scene requires walla — low-level, indistinct background conversation — blended beneath the main dialogue to establish the environment without drawing attention.