Thanks for the additional information. It is helpful. There are some medical conditions that can cause sudden aggression and those may be a factor but it sounds more behavioral to me. Unfortunately, medical causes can not be ruled out without testing.
It sounds like your dog may be having issues with dominance aggression when in the house. Many dominant dogs are described as well behaved until you try to get them to do something they do not want to do, and then they reprimand you either with a growl or bite if you don't heed the growl. Things like taking away something they want, making them move when they don't want to, waking them up, etc can cause them to reprimand (bite) you or other household members. Now there can be a dominant male and a dominant female, so he may not feel the same need to reprimand you as he does your husband. Your husband would be a "threat" to him being boss, so he would be more inclined to reprimand your husband since he is male.
Dogs that are allowed on tend to feel that since they are elevated to your level or higher if on your lap, they mentally feel elevated as well in the pack order and thus are the boss. Keeping them on the floor can help lower them mentally back to a submissive position in the pack. So the first thing is to not allow him higher that the humans or even on the same level. In addition, humans shouldn't be on the floor with him either. Attach a leash and use it to remove him from the furniture. Give a correction in the form of a quick tug and firm "NO" when he attempts to get on and a treat when he starts not trying to get on the furniture. Thus you are providing negative reinforcement for the getting on the furniture and positive reinforcement for the desired behavior (not attempting to get on the furniture). Now this doesn't have to be permanent but at least for 2 weeks after he stops trying to get up. After that, IF he performs a command, he can earn the privilege of getting on the couch but must get down on command. I would not allow him back in your bed, though. So get him his own bed that is lower than yours.
There are other ways to regain the dominant position in the house as well. The best way is to start obedience training. While a formal training class is great, you can start obedience training without a formal class. Before you can get into classes, I am including links to a site that teaches some good methods of training. Be sure and click on the link to the page on obedience at the bottom. and links on subsequent pages leading to detailed instructions.
Training works best if you train at least 30 minutes a day (two 15 minute sessions). I would start making your dog work via the Nothing in life is free program (NILF). It is outlined below.
Now you can train with him, but the bulk of training should be done by your husband. Have him use tasty paper thin hot dog slices as treats since dogs like to obey for that treat. Each time he obeys (even if for treats) it makes them a little more submissive to the person giving the command.
You will also want to keep a leash on him at all times initially to grab if he should disobey. I think you will be pleasantly surprised at how well your dog does with training. Dogs like knowing what is expected of them and they love the little paper thin slices of hotdogs that I use for treats while training. Give this a try and see how it works for you.
You can also do the following specialized training with him. Each time your dog barks at your husband, give him a short tug for a correction and tell him “NO” in a low firm tone. Dog’s growl when they are commanding other dogs which is why you used a low firm tone. Do this each time. I realize it may be an ongoing battle. You may do training where your husband is sitting and then stands ups in the room, you make the correction and your husband sits back down. Make the correction as soon as he starts to bark or fixates on your husband. Have small tasty treats like the hotdog slices ready. If your dog does not bark or go after your husband, praise him and give him a small treat. Practice this often. Each time he doesn’t bark, give him a treat. Before you know it, he’ll be associating you husband and not barking with getting treats and praise. At this point you will want to cut back on the treats and make them a sometime reward with the praise being the reward. Remember, the correction should not be hard, or choking, just a quick short tug, to break his concentration while you tell him “NO”.
You should try all these techniques in conjunction with one another. It usually takes more than one technique to solve a problem. I hope this information is helpful to you and you are satisfied with my response. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have .