There is a scientific name for nasal rhinolalia. The same concept also means a change in the timbre of the voice, the pronunciation of sounds (this is due to a violation of a certain function in the nasal cavity). There can be many reasons for nasal nasalism, and the treatment of nasal nasal should come from them.
So, the reason for the nasal tone can be insufficient mobility of the soft palate, the irregular shape of the tongue when extracting sounds (this reason is the most common). It can also be caused by defects in the hard and soft palate, adenoids (difficulty in nasal breathing), rhinitis (inflammation of the nasal mucosa), and a deviated nasal septum or injury. Close your lips, open your jaw and sing the melody. On the inside of your lips, you should feel a slight tickling sensation. You can also pinch your nose and say the whole alphabet without the "m" and "n". If it's okay, nasal is not your story.
In the event that you are not completely sure whether you have nasalness, you can check it with a simple exercise. You need to close your lips, open your jaw and try to sing a melody. At the same time, from the inside of the lips, you will feel a slight vibration, tickling. Didn't you feel it? So, you have to go to a specialist or try to get rid of nasal nasalism on your own. There is one more exercise to check: pinch your nose and tell the whole alphabet, but without the letters "H" and "M".
It is possible to eliminate nasal nasalism, as already mentioned, on your own with the help of various exercises that develop the mobility of the soft palate. However, if you have anatomical abnormalities, then most likely you will need special treatment (surgery). Often, you can get rid of rhinolalia when working with a speech therapist.
Exercises will not be superfluous either. One of them is an exercise called Yawn. Its name reflects the essence of the entire technique. You just have to practice the ability to quickly transfer air from the nose to the mouth. So just yawn more often, both with your mouth open and with your mouth closed.
The next exercise is called the Vowel Table. There is nothing difficult: it is necessary to pronounce the sounds I, E, A, O, U, Y in turn. Then you have to inhale and add the sound "M" to each vowel spoken. That is, further you will need to pronounce already MI, ME, MA, MO, MU, WE. Do a similar work with the letter N.