Undesired noise might be heard due to incorrect device configuration.
When more than one microphone is connected, howling may occur due to multiple sound inputs. Disable all unused devices except the connecting one.
Noise may occur when microphone and sound output strength are different.
In a public place, try wearing earphones before joining a meeting.
Howling is likely to occur if you choose to output sound through the speaker of another device while using a speakerphone. When using a speakerphone, set the microphone/speaker to the same device.