No sound come out from dell 34" ultra wide monitor after connected with my Dell XPS 13 laptop

After connected my dell XPS 13 with Dell 34" ultra monitor via Kensington SD4000 universal docking station. Have video but no sound coming out from my ultra wide monitor. The only sound that I heard was from the XPS laptop. My Laptop's OS is window 10 and I tried to use Chrome and explorer Edge, none of the search engine is able to solve the problem. Moreover, I checked my all connective cables to/from the docking station and it seems fine to me. Please help!!!!!!!!!!!!