A microphone blocker is an adapter designed to prevent eavesdropping.
A microphone blocking plug
Two microphone blocking plugs with USB C interfaces
Mic-Lock USB-C Microphone blocking adaptor with mobile telephone earphones
A phone connector is a family of cylindrically shaped electrical connectors primarily for analog audio signals. Invented in the late 19th century for telephone switchboards, the phone connector remain
Microphone blocker
…connector providing a microphone emulator so that the phones microphone is disabled. Products available include those with: USB-C, Thunderbolt and 3.5mm TTRS male plugs and female connectors (with a keychain hole, or a small strap attached directly to smartphone cases) to prevent loss when the male connector…
Phone plug mated in a phone socket. The plug's grooved tip is held firmly by the socket's spring tip contact. When not mated, this spring instead connects to the flat switch contact for detecting a plug.
TS and TRS plugs of different sizes
Old connectors. On the top is a TRS socket. Plugs are below. The leftmost is a TRS plug; the rest are TS plugs.
Modern profile 1⁄4 in TS plugs