上麦

Comes from livestream and audio-room culture (语音房 / Clubhouse-style apps). When a viewer is invited from the audience to speak with the host, that's 上麦. Opposite: 下麦 (xiàmài) 'leave the mic.' Related: 连麦 (liánmài) 'mic-link' = host connects to another streamer's mic.

usage

麦 here is the clipped form of 麦克风 (màikèfēng) 'microphone.' On stage in a 综艺 variety show, you might also hear it metaphorically — 上麦 = take your turn at the mic.