GPS with no audio questions & water

[landlover 5]

Hi, took some time off riding and a GPS sounds wonderful. Is it practical to use the GPS without audio? Do not want to buy custom earplugs with speakers have earplugs now and like to hear the motor, horns and emergency vehicle sirens. It may be a silly question but don't want to buy a GPS and then find out a month later this is not working like I wanted it to.

 

How do you all make a cheap GPS waterproof and is it also practical. I do not have a smartphone.