i copy/paste file “notes” from my smartphone into my pc,when i open this file from my pc is empty while is not?

i want to hear the sound clips i have recorded but when i open the folder "notes" i have copy/paste from my iphone, no files are shown. but when i see the properties of the folder there seems to be some files in it and also it is 4,50 mb . what can i do to hear those files from my pc ? is there a specific app ?