The pinhole beside the lenses is often a microphone port
On many smartphones, the tiny opening near the rear camera gives sound access to a microphone tucked inside the phone. The opening is small because the microphone itself is a compact component; the visible dot is simply the route sound takes through the casing.
When you record video, that microphone captures nearby sound while the camera records the scene. Its position near the camera can help the phone pick up audio from the direction you are filming, though the exact pickup pattern depends on the phone’s microphone design and software.
A small opening with a practical job
The port also lets engineers place a microphone without leaving a large, exposed component on the phone’s back. Inside, software can combine input from multiple microphones to reduce steady background noise or make recorded speech clearer. The tiny hole is therefore part of an audio system, not a second camera lens.
Not every dot beside a camera has the same purpose: some phones place focusing or depth-sensing components in that area. But when the opening is a microphone port, covering it with a finger or a thick case can muffle video sound—even though the phone’s main microphones elsewhere may still record.
