Mumble

Mumble is a word in the English language that refers to speaking in a low, indistinct, or muffled manner. To mumble is to utter syllables unclearly, often with a soft or inaudible tone. The term is frequently used to describe a speaker who speaks quietly or unclearly, making it difficult for others to understand. Its etymology is generally treated as onomatopoeic or imitative of the sound of indistinct speech.

Mumble also denotes a free, open-source voice communication application designed for low-latency, secure group conversations. It consists of a client program and a server component (Murmur) that handles authentication, routing, and access control. The software is cross-platform, supporting Windows, macOS, Linux, and mobile clients. It is popular for online gaming and communities that require private or moderated voice chat. Features include push-to-talk and voice-activated transmission, noise suppression, and positional audio that simulates the spatial location of participants. All client-server communications are encrypted, using TLS, and the server provides channel-based permissions and moderation tools.

The project is maintained by volunteers and has a community-driven ecosystem of plugins and documentation. While less widely adopted than some commercial VoIP services, Mumble is recognized for its emphasis on privacy, low latency, and configurable moderation.