my friends say I sound like I am far away in a tunnel when I use my 60's Micro

can I do anything to make the sound clearer? I have an LG Arista android smart phone

if the sound is not clear you may want to check the following:
1) Some phone covers prevent the audio plug to be pushed in all the way. This may lead to all kind of audio problems due to poor electrical contact.
Remove the protective cover and try again. It is essential that the plug snaps in at end position when pushed in. You may also test the handset with another mobile phone. If the problem persists it the handset is very likely defective.

2) Make sure the microphone part of the handset is held in front of the face. It should not be under your chin. This could also lead to a muffled sound. Seems obvious but it is case solver a lot of times

3) Test your phone with another headset. If the sound is the same the problem is with the phone (audio jack??).

Hope that helps!