The trunk is divided into the thoracic cavity above and the abdominal cavity below by the thoracic diaphragm. The vocal cords are located in the upper region of the thoracic cavity, in the area between the folds known as the larynx. The pelvic floor is a multilayered muscular sling that is located in the lower part of the abdomen. There is a relationship between the pelvic floor and the larynx through fascial connections along the trunk .

Pelvic floor muscles (PFM) play an important role in bowel and bladder continence, sexual function, lift abdominal and pelvic organs, regulation of intra-abdominal pressure and maintenance of respiration and posture. The larynx has many important functions such as protecting the airway, facilitating natural breathing, producing phonation or sound, increasing intra-abdominal pressure during straining, defecation, micturition and labour. Structural integrity and functionality between the respiratory, laryngeal or phonation levels and the resonant cavities are essential for correct voice production. The pelvic floor, thoracic diaphragm and larynx move simultaneously caudally when inhaling and cranially when exhaling, like a piston.

Voice is produced by the larynx during expiration when air passes through the trachea, setting the vocal cords into vibration. The tension of the vocal cords and sufficient subglottal pressure are essential for phonation. Additionally, the abdominal muscles play a crucial role in controlling the expiratory phase of speech by counteracting the recoil pressures of the lungs. This allows for the production of longer utterances and the maintenance of subglottal pressure throughout phonation.Voice hygiene and proper breathing techniques are crucial for both professional and non-professional voice users such as singers, academics, call center employees, and religious leaders. Healthy sound production requires PFM stability, balanced abdominal muscles, and effective respiratory control

Inclusion Criteria:

• Being volunteer
• Age between 18- 40 years

Exclusion Criteria:

1. urological, gynecological, respiratory, or vocal disorders,
2. cognitive or perceptual problems,
3. being pregnant,
4. being in the premenstrual or menstrual phase on the evaluation day,
5. having allergies, cold, or flu on the evaluation day,
6. perineal sensitivity,
7. any surgery in the abdominal, stomach, respiratory, laryngeal, and/or head and neck regions,
8. vocal complaints for at least 15 days,
9. hearing complaints.

Healthy volunteers