You can adjust the equalizer to boost the frequency of speech or decline the frequency of sound effects. Not sure if LGs have it, but also volume levelling can help too, or night mode.
TVs will often have sound presets like 'Speech' that do this for you.
A lot of the problem is with the source, with programs mixing sound effects louder, and speech quieter, I have the same trouble with shows nowadays.
A soundbar can usually help a lot, but it can depend on the sound signature and also the preset you have that set too. If the soundbar has a central tweeter and woofer with a sound signature boosting mids speech can be very clear but if there's no woofer, or it has a dark and muddy signature then its not going to be clear.
Same advice with TVs applies to soundbars also, sometimes they too have volume levelling, night mode or modes that boost speech.