Two-way audio uses a microphone, a speaker and an audio codec so an operator can hear and speak through a device. On cameras and intercoms it supports talk-down, visitor screening and remote assistance, and it carries privacy obligations because it captures conversations as well as images.
Audio changes a camera from a recorder into an intercom. That is useful at a gate or a delivery door, and it is legally different from recording video in many places.
Hardware and audio quality
A built-in microphone and speaker are convenient but pick up wind, traffic and mechanical noise. Half-duplex devices sound like a radio, while full-duplex with echo cancellation resembles a phone call.
Privacy and consent
Signage, retention limits and a clear rule on who may listen are part of the design. Audio retention often has different legal requirements from video, so check both before enabling it.
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