I bought a 3yr old pug who turned out to be deaf, the fence issue is V important but hand signals and clapping to draw attention ,as they seem to respond to the rythm; also if sleeping and wanting to attract attn I used to gently nudge her to wake her to go to bed.
she seemed to be able to hear v high pitched noises and bark when the others didn't, the best thing is ahearing companion who will be the deaf dog's ears.