Some credit to Walkazo for the whiteboard bit. Most of this is based off of the book canon, or at least the ending is.
I had an accident when I was four.
It was when I had begun to discover my love of creating music. I had always loved performing, but creating had a certain flair to it that left me entranced by allowing the notes to flow onto pages in whatever form I saw fit. I didn't need to be restricted by the minds of others or permit them to tell me what to do. I could make my own music, and design it the way I wanted to. It wasn't easy, but I greatly enjoyed it, and my enhanced intelligence allowed me to create things that sounded beautiful.
Or at least, they would have sounded beautiful, if I could actually hear them.
You see, at that point in my life, I despised personal hygiene. I would hide out in the filthiest places possible, avoid every attempt to give me a bath, in order to continue my musical compositions. Of course, I realize now how completely idiotic this was, but I was only four at the time, and my intelligence had not developed to comprehending the importance of cleanliness, especially with my type of hair.
So day after day I sat in filth, avoiding any attempts for washing. I was unsuccessful on occasion, but the majority of the time I managed to avoid the quotidian task. My unkempt hair earned me the nickname 'Kooky' from my family.
This inevitably caused my demise.
One day, I cannot say for certain which day, as dates were not important to me back then, I awoke to an odd quiet, and a strange pain within my ears. I did not mind the silence, and quite frankly, it was nice to avoid waking to the sounds of screaming siblings and chaotic minions. As for the pain, I figured that it would pass over time and I did not concern myself with it. I didn't notice the time, that it was much later than my alarm had been set, and so began a strange, and silent, sequence of events.
First, breakfast… well, actually, lunch. I had awoken at 11:47 if my memory serves me correctly, for it took me ten minutes to get to the dining room at that age, where it was 11:57.
At any rate, everyone else was already there. Mother gave me a concerned look, and opened her mouth to ask me a question. I am still unsure of whether she actually did or not.
Regardless, the servants soon brought out our meals, and we began to indulge in what they had prepared: simple sandwiches. I was surprised that we were eating sandwiches for breakfast. It was definitely an interesting change of pace.
Now, during our meals, I will often think up different symphonies, and I used to have a subtle habit of humming them, a habit I have long since broken, as far as I know. My father could not stand humming, and usually I was able to catch myself before he noticed or before I could be punished if he did. Simply stating my name in a warning tone would be enough. Unfortunately, as I could not hear myself humming, I never noticed that I was doing it. Father, according to the others, ordered me to stop, but we obviously know why I did not obey. I happened to cast a glance over at my mother, who was staring at me. I turned back to my meal, oblivious to my father's orders. I was lost in my own thoughts, until a large blow struck my cheek. I burst into tears, completely baffled at the sudden attack. My father, next to my chair, stormed off in fury and slammed the door behind him. The noise startled the others, making them jump. I did not respond. Mother tilted her head as she comforted me gently, gears turning in her head while she rustled my filthy hair.
We each got a cookie after we ate, and I did not complain. Cookies after breakfast was something I had always longed for. And it helped sooth the pain in my face. Mother was giving me an odd look while we finished our meal.
While Iggy curled up into Mother's lap to sleep after his own special meal, I took Lemmy and Roy along to play after we had eaten, carrying the latter as Lemmy rolled along down the hallway. I did not hear Mother's call. Roy gave me a look of prompt, as if he expected me to say something, or react in some way, as we left the dining room.
The tears on my face had mostly dried by this point, and by the time we reached the toy room I was my usual self. I was attempting to teach Roy how to walk, as he had not mastered the simple task yet, and while he could stumble a few feet, I wanted to make sure he wasn't going to fall if he ran off on his own. He opened his mouth to whine, and I let out a sigh before I replied. I had guessed what he would say before he could say it. What I did not realize was that he had already spoken.
"You must learn to valk eef you vish to play!" I had calmly replied. That was when I froze and realized something. I had felt my vocal cords vibrate and words expel from my mouth…
…but I had not heard them.
Baffled, I stared down at my hands and clapped them together. No sound. Not even a whisper. Uncertain as to what was going on, I clapped again. And again. The puzzlement increased within me as to why my hands made no noise when I hit them together in standard fashion. Around this time my mother arrived and called me.
"Ludwig? Could you come here?"
Obviously I could not, having no idea that she was present at all.
"Wudwud, mama caw ya!" Roy prompted, glancing at me. I stared back, unsure as to what he wanted and why he would not speak. In fact, I wondered why no one was speaking at all this day.
As reported by my siblings, Mother approached behind me and smacked her hands together very loudly. That would explain why Lemmy unexpectedly fell off of his circus ball for no apparent reason…
A tap on my shoulder startled me, and I spun around in fright. Mother looked down at me, visibly concerned, and picked me up, much to my disdain. She took me, squirming, to Kamek. I figured I was in trouble, and did not want to be punished for nothing twice in one day.
Mother forced me to sit, and Kamek examined the sides of my head. He took a black marker and wrote something down on a paper-sized whiteboard. Showing me the whiteboard, I read the words that he had written. It was a good thing my intelligence had advanced far beyond my age, for otherwise I would not have comprehended what he had attempted to relay to me.
Prince Ludwig, you have a very severe ear infection, which has damaged your ear drums. You have gone deaf.
Thunderstruck was not even close to describing the sentiment I felt at that moment. Way to put it down easy, Kamek…
I suppose he had said it as he wrote, because my mother clutched my shoulders tightly right before I saw the words.
He erased what I had read and wrote something new:
Whether or not this is permanent, I cannot say. But I do know that this was caused by your bad hygiene habits, which must come to an end immediately. I will give you some antibiotics from the medical ward to clear your ear infection. Hopefully this deafness won't last.
I hated the fact that I would have to have a bath now, but being deaf was even worse. Now I could no longer hear my music. That upset me more than my physical condition, and I cried a lot that week. Father came and comforted me because of slapping him, apologizing despite the fact that I couldn't hear him.
After being treated, I continued to write music. However, considering that I wrote by ear, I never knew if what I was creating was pleasant or not. To boost my self-esteem, I bragged about my symphonies and forced my family to listen to them. Which they hated. Father, not being able to stand it anymore, locked me in one of the labs for a week. There, out of boredom, I discovered my love for inventing machines as another hobby as opposed to inventing music. I realized machines, like music, had their own patterns and rhythms and flow. This assisted me in creating many things within that week of punishment, and while some were failures, I learned from the books that were located there, and I grew in my knowledge of machinery, able to improve my designs.
When my punishment was up, how stunned Bowser was to see the numerous devices I had made! He was proud of me, and permitted me to keep playing my Koopa Symphonies, much to the family's chagrin.
I learned to read lips in order to tell what my siblings were saying. For the most part, it was not too hard. There were a few mistakes and misinterpretations, but I managed fairly fine without my ears.
Two years later, in our first battle with the pesky plumbers, I received three blows to the head by the boot of Mario. The first two did nothing, but the third…
"OW!"
I sat up stunned when I heard my voice.
"I… I can hear again! I'm not deaf anymore!"
Needless to say, Mario continued on in confusion. I shared the news with my family joyously, and despite our loss, it was a night for celebration. I played one of my symphonies.
Which I immediately discovered was atrocious. I burned every sheet of music I had made over the past two years and immediately started fresh that night. My family had an even greater celebration the next day… I was unsure whether I should have felt insulted or not…
I had an accident when I was four.
Because of it I could not hear for two years of my life.
But I also learned how to invent things.
Whether it's a happy ending or not… I will let you decide.