Play NYT Connections Puzzle #681 Thu, Mar 20

Find groups of four related words Need hints?

Solve NYT Connections puzzle #681 - Group 16 words into 4 categories: DIRECT, FRANK, LOUD, VOCAL, BAY, CHANNEL, SOUND, STRAIT, BUNGEE, EXTENSION, SPINAL, UMBILICAL, GENIE, LIGHTNING, MESSAGE, SHIP.