Deaf ponies use morse code to speak.

Pegasi use their wings for the most part while earth ponies use their ears, unicorns can use magic to speak by floating words in the air manga style, Pegusi will use their ears if their already flying to avoid accidents and sometines earth ponies use their hooves via stomp and dig, unicorns will do the same if the manga bubble is in the way.

Hearing aids aren't exactly a thing in mlp as while they are advanced they are still pretty behind in terms of technology. If they did exist, it's probably an uncomfortable smallish horn attached to their ears to try and amplify the sounds around them.

Alright, so to start, I loved Gen 5. I wish it could have continued, but I understand why it couldn't. I would also be up for a reboot of Gen 5 with the same characters but with a different story. Seriously, I felt there was so much potential with these characters.

Either way with the end of the series I thought I would share a bit about what I would do if I changed it.

To start I would change the ending of the movie. I would have it be where Sunny does get the wings and horn but they were only there as a symbol. Similar to the ending of the music video "My past is not today" I would also make the crystal shatter at the end to show they are not needed anymore.

Next, I would still have a bit of Gen 4 lore but not be so dependent on it, specifically the main 6 of Gen 4. Instead, I would keep them as heroes, but the separation of ponies came AFTER their time. This is because I never thought alicorns were immortal; they just have a longer life. I would also keep landmarks and similar animals.

I would also make the crystal's creator be someone else. I am thinking Flurry Heart as an adult.

Here is what I am thinking. During Flurry's rule Twilight and Cadence were retired like Luna and Celestia. Maybe even gone if you want to get dark. Either way, she eventually meets Opaline. (I seriously hated the idea of her being from the same time as young Luna and Celestia and yet is the only one still alive. Seriously? There was no logic there) They become enemies and eventually fight. However with trickery, Opaline wins. kind of. You see, before Flurry is defended aka banished she realizes that the pony kind would fall to ruin because of Opaline and the ponies fighting so to stop it she created the crystals and scattered them. At the same time, she is banished and now Opaline is trapped in a world without magic. Take note Flurry Heart made it a condition that to get magic back ponies have to unite again. Something that would never happen with Opaline in charge.

That is pretty much the backstory of the crystals. After magic returns, there is no need for them again so they shatter and magic returns permanently. Opaline who is still around but was in a hibernation state (not sure how yet. maybe discord or dragons?) returns and while getting a grasp of the new era she plans her counterattack. Meanwhile, Flurry tried to contact someone to help her get free and help defeat Opaline.

Off-track thoughts:

Maybe Misty is the only one that can hear Flurry's voice and that is why she joins the gang and why Opaline targets her.

Maybe at the end, they all hear Flurry’s voice, free her and with Flurry Heart and the new mane 6 working together they defeat Opaline.  Not says Flurry will stay though.  I think she will retire too and travel the new world similar to what StarSwirl the bearded did once he was free.

Oh maybe Flurry was the princess of unity and passed the title on to Sunny after she pulls a Celestia and makes Sunny a princess.  

An animal growls, snarls or hisses at her and she's had enough? She'll do it Right Back.

The group has to track something/somepony down? Next thing you know Fluttershy is howling up into the air and a pack of wolves emerges from the woods in order to lend a paw.

Applejack needs help herding some cows or sheep and Winona is injured/sick/away at the moment? Here comes Fluttershy nipping at their heels and barking at them to round them up.

Somepony needs help digging a hole but they don't have any shovels? Cue Fluttershy expertly digging into the earth directly with her hooves like a mole.

Somepony needs help carrying something heavy and Applejack isn't around? There goes Fluttershy lifting up something twice her size like it was nothing, almost like she's an ant.

She. Can sleep. Anywhere. In a tree like a leopard. Upside down like a bat. Standing up like...well, a horse. Buried in the sand like a crab. In a rocky cave like a bear. Halfway in water like a seal. An. Ny. Where.

Rubs cheeks against friends and family like a cat. Will sometimes try to lick you too groom you. Will carry things around in her mouth.

So this is just a quick thought I had late at night. might edit this later but these are the basic ideas for what I would do with the gen 5 characters. As you will see most of them I will keep the same with a few minor changes.

Sunny - I would keep her leadership characteristics but I would increase her curiosity.  I would have her want to go on adventures when they present themselves and when not present she would want to explore the new lands now open to her.  She will also ask questions.  A lot of questions. To an almost obsessive level like she was in the movie.  However I would keep her level headed so she would only ask questions when she was able to.  I would even throw in a bit of twilight and have her be a bit obsessive with keeping ponies together and sometimes losing sight of what is in front of her.

Izzy - For izzy I would keep her goofy and creative but I would add a lot more depressing moments for her.  I liked how some things would instantly get her upset in the movie and wish they kept that. I would also have her be a bit bad at speaking her mind when she is in one of these moods.  I would also get rid of her cluelessness that she seemed to have in “Tell Your Tale”.  I think she was more aware than what was shown there.  I would make her more serious when it was needed even if she does get distracted with a new craft idea.  I would also reintroduce her luminescence ability.  With it she would struggle with other ponies' moods and try to help even if it is not needed.

Hitch - I would make him a lot more serious.  Maybe even a perfectionist.  He does what is needed immediately no matter what.  However I will have him struggle with situations that are lawfully right but morally wrong.  I would also make him a more competent detective than he was in the show.  

Pipp - I would honestly get rid of the hair stylist idea and keep her as a full time influencer.  I would want her to be really glued to her phone and struggle with reality.  I would make her still care for others.  However she firmly believes the best thing to help someone or something is to post about it.  She will really struggle with backlash but will get back to posting after a while.  I will also have her struggle with zipp on who should be queen.

Zipp  - I would make her a dare devil like normal but she is much more willing to help pegasi learn to fly.  I would make her have a dream to bring back the Wonderbolts.  She will be someone like spitfire but a bit more impatient.  I would make her be a little hot headed when things don’t go as planned.  I would also get rid of her detective side and just have her be a common assistant to everyone.  She is also more open with not wanting to be queen which will make her but heads with Pipp. 

Misty - I would honestly keep her mostly the same. if I was to change something is maybe her a put more opinionated. I wouldn't have her be with Opaline for most of her life so she wouldn't get the fearfully side to her. Would still keep her shy and nervous but once she makes friends she is a lot more open with what she likes.