To do Donald Duck’s voice impression you’ll have to learn the correct tongue placement, raise the pitch of your voice, sound incomprehensible, watch lots of Donald Duck’s cartoons and record yourself for feedback.
Watch tons of Donald Duck
First of all, watch lots of Donald Duck’s cartoons. It’ll help you catch his pitch, manner of speech and tantrum habits. If you’ve noticed, he usually goes on angry tantrums due to some kind of failure.
Put the tongue against upper teeth
To mimic Donald’s voice put the tongue against the inside of the upper teeth in your mouth and speak into one of your cheeks. The middle part of your tongue will likely bend to one side, creating a banana shaped tongue.
When making the sound your tongue should vibrate a bit and create quick and sharp ‘kch’ sounds. This will add the duck voice quality to your Donald Duck impression.
Use higher pitch voice
Donald speaks in a higher pitch voice, hence raise the pitch quite a bit. Your voice should sound very quick and sharp, almost piercing like, but with quick interruption.
To speak in a higher pitch voice focus on the upper part of your mouth, that’s where the sound should resonate and come from. You can also read more about how to train and achieve a higher pitch voice here.
The tongue positioning and sharp manner of speech should make you sound quite incomprehensible and that’s fine. If you’ve watched Donald Duck’s cartoons then you would notice that most of the time it’s impossible to understand what Donald is speaking. Therefore, you don’t need to achieve a good articulation when doing his voice impression, remember that he’s a duck and doesn’t speak clearly.
Copy the same sentences he’s using
When you’re watching Donald Duck write down or memorize some sentences and try to repeat them or even better listen to his pronunciation and try to repeat it immediately. This way it’ll be easier to learn the voice impression than speaking in random sentences. Once you’ve managed to copy the same phrases in the perfect voice of Donald Duck, then you can practice with random phrases of yours.
Finally, keep recording yourself and comparing it to the original voice. This way you’ll notice the flaws in your voice impression and it’ll give you a sense of accomplishment since you’ll struggle at first but should see improvements with time.