Oh my, they are all the same aren't they?
First of all, relax!! Your kid is only 18 months old... The right age to start separating
your will from
his will. Plus, he's deaf, which doesn't have anything to do with discipline I guess, but it's a powerful weapon!!! My son has always used his superpowers. I can make his hearing sister fell intimidated, scared, guilty just by talking to her (well poor thing, I try not to of course, but I'm lucky as she's a reasonable child). Even with her door closed she can hear me shout "Put your toys away when you're finished playiiiiing!".
But he...:roll: If I say "no" he just needs to turn away, and I don't exist anymore. He takes his aids off, and the world is at his feet. No limits. And he knows that!
So yes, you'll need to find new strategies. But you know, that's it with kids! What worked with one doesn't with the next. I have a friend with 7 kids and she says it was the same with every new kid. They're all different!
First I think you shouldn't take deafness as a reason for everything. Yes, your kid has a linguistic delay, both in speech and sign (because he's not born in a signing family, just like mine, so he's just started being exposed to sign, and it takes time for that too). But this happens to hearing kids, too. Late talkers are often trapped in the same frustration. It's not a definitive thing - your kid grows up day after day. It will take TIME.
Second, of course you need to be as visual as you can: signs, gestures, facial expression. Some drawing may work too. But every kid is different, you need to try many things.
I can tell you what works with my kid:
-Not getting too angry. Showing an excessively interesting reaction makes him want to try again, even if consequences are bad for him. He just can't resist.
-Saying and signing "NO" calmly and firmly... And only when it's REALLY needed. I always say, if you can say "yes", just do. Many "no"s, (especially if they can possibly then become "Oh well ok then do what you want!") are BAD. We need to be clear: no is no, and it comes when it's impossible for me to say "yes". So that he can trust you, that your not making fuss :P your "no" has a precise reason to be.
-If he insists, make it phisically impossible for him to go ahead: block him, put the thing he's not using properly away, things like that. He's stubborn, but I am, too. And if I said "no", it's because that thing is WRONG, so if you don't stop, I'll stop you. Period. I'll wipe away your tears with kisses later, but won't let you do that.
-Explaining, with signs and words, manymanymany times. It always seems not to work at the moment, but it does.
-TONS of PATIENCE. Deaf kids are experimental. Being told "no" and explained why is not enough. They need to try the same thing maaaaany times before accepting your "no". Be patient. You may be rewarded as we are by a kid who points out things and sign "No" to himself.
I tell you, my son is 3yo. He was pretty wild and I've been often told I should discipline him more. But that's not my way, I'm sort of a hippie mama and I don't like getting angry at kids. But he eventually became a well behaved kid. Doesn't make tantrums, doesn't cross roads, goes to kindergarten, speech therapy, everything, without a problem and with a smile on his face. He's got a strong personality, but I don't find him to be a fussy kid at all. And believe me, he WAS pretty wild and WAS and IS frustrated by the difficulties in communication.
Patience is the key, I think!