For some reason the feedback voice on S-Voice is no longer working. The app works but there's no voice response and on the bottom left there's a circle with a line through it but nothing happens when I tap on it. All other voices on the phone work.

Anyone know how I bring it back?

Open s-voice, touch the 3 dots and the top option should be "Enable Voice feedback".

Which 3 dots?

The 3 dots that bring up menus on Android, in the top right corner.

http://s19.postimg.org/ipp7es8gj/image.jpg

I don't seem to have those....

What version of Android are you using?

Try the left hand soft key (next to the home button) and see if the menu is there.

Lollipop. I tried that too and it brings up settings but nothing that says about activating the voice.

My screenshot was from my S5 with Lollipop and I'm sure I remember having the 3 dots menu when I had an s4, so why you don't is puzzling..

Have you checked the s-voice menu in Settings? (Though I don't have the "Enable Voice feedback" option there, only in the in-app menu).

Otherwise you might need to consider a full reset.

Just use Google Now. S-Voice was and is terrible.