Does anyone know if it's possible to connect a TS unbalanced mic to a PC?

 

I have a standard CTIA 3.5mm TRRS jack on my Lenovo ThinkCentre M75q gen2. I got myself this Y-splitter from Jaycar: https://www.jaycar.co.nz/3-5mm-4-pole-plug-to-2-x-3-5mm-socket-cable-250mm/p/WA7020

 

 

The headphones seem to work, but the mic doesn't. Tried it on my laptop's 3.5mm TRRS jack - same thing. Tried a different TS mic - same thing again. My guess is that the Y-splitter mic input expects a TRS connector; but what difference does it make is beyond me. Does anyone know if there's a way to overcome that?