Neck Circumference and Vocal Parameters in Women Before and After Bariatric Surgery

Morbidly obese patients may suffer from vocal disorders, as vocal production is directly related to the volume of the vocal tract, and the large-scale accumulation of fat in this region may interfere with voice production. The aim of this study was to analyze the neck circumference, fundamental frequency, and maximum phonation time of a group of morbidly obese women before and after bariatric surgery.

An observational, longitudinal, and descriptive study was performed with patients of the Obesity and Related Diseases Surgery Unit of a university hospital. A total of 21 morbidly obese women aged 28-68 years, with a mean age of 41.33 years, participated in the study. Neck circumference was measured using a tape measure. To obtain fundamental frequency values, the patient was asked to produce the vowel [a] at normal intensity and pitch for an average period of 3 s. After recording, the participants were asked to produce the sustained vowels [a], [i], and [u] at normal intensity and pitch, with a stopwatch used to measure maximum phonation time. Eight months after surgery, patients were reassessed using the same data collecting procedures as were carried out prior to surgery.

After surgery, there was an increase in the average value of fundamental frequency and maximum phonation time for all the vowels and a reduction in neck circumference. The differences were statistically significant.

Weight reduction and a consequent decrease in neck circumference affected the changes in maximum phonation time and fundamental frequency values in the voices of these patients, after weight loss.