Assessment of pronunciation before adenoidectomy: unable to pronounce / m / 21.3%, / n / 34.6%, / ng / 59.6%, / nh / 61.2%; 2 weeks after adenoidectomy: unable to pronounce sounds / m / 5.6%, / n / 8.3%, / ng/11.1%, / nh / 8.3%. Assessment of sound quality through analysis of neutral tones is the vowel / a/.