Is it ok to let my 18 month old watch 2-3 minute cartoons a few times a week? Or is no digital viewing advised till they're 2?

It really makes my job easier as in can just let my son watch tv while i get my things done. However around 18months time i notice my son speech seems abit delayed and thats when i decided to stop all tv for him. Surprisingly after stopping tv for around 1 or 2 weeks, he starts talking quite alot. So i feel it really makes a difference