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Completed

NCT Number: NCT07111650

Relation of Pelvic Floor Muscle and Phonation

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

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Key information

Conditions

Healthy

Age range

18 year–40 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Kutahya Health Sciences University, Kütahya, Merkez, Turkey (Türkiye)

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Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Being volunteer
  • Age between 18- 40 years

Exclusion criteria

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

Treatment and study plan

Primary outcomes

  1. Pelvic floor muscle activity

    Time frame: Baseline

    Pelvic floor muscle strength and endurance were assessed using the Neurotrac® Myoplus 2 Pro two-channel EMG Biofeedback device. One channel's electrodes were placed in the anal region to assess the pelvic floor muscles, while the other channel's electrodes were placed on the transversus abdominis, with a reference electrode located on the thigh. Initially, the participant was instructed on how to contract and relax the pelvic floor muscles, followed by a trial period.

  2. Acoustic Voice Analysis

    Time frame: Baseline

    Both the recordings and the analyses were performed in the same laboratory using the Kay Elemetrics Computerised Speech Lab (CSL) KayPENTAX Model 4500 system. Recordings were made using a KayPENTAX CSL Model 4500 unit and a Shure SM48 microphone connected to a desktop computer. Participants were seated on a chair in front of the computer, and the microphone was positioned at a 45-degree angle, 10 cm away from the speaker's mouth. All recordings were saved in the CSL programme as sound files (nsp) with a sampling rate of 44.01 kHz and a resolution of 24-bits. Data analyses were performed on the same computer and device. Participants were instructed to produce a natural and relaxed /a/ phonation without straining or raising their voice, similar to how they normally speak in daily life.

Secondary outcomes

  1. Maximum phonation time

    Time frame: Baseline

    Voice recordings for maximum phonation time (MPT) were recorded using the CSL device, and analyses were performed on the same system. For the MPT, participants were instructed to take a deep breath and produce a long /a/ phonation at a normal pitch and loudness until they ran out of breath, without holding or pausing their breath. This measurement was repeated three times, and the average duration across the three trials was calculated in seconds.

  2. s/z ratio

    Time frame: Baseline

    Voice recordings for the s/z ratio were recorded using the CSL device, and analyses were performed. For the s/z ratio, participants were asked to take a deep breath and produce a long /s/ phonation at a normal pitch and loudness until they ran out of breath. The entire procedure was repeated three times. They were instructed to perform the same process three times with the /z/ phonation. After calculating the maximum duration of both /s/ and /z/ phonations, the s/z ratio was determined by dividing the maximum /s/ duration by the maximum /z/ duration.

Sponsors and collaborators

Lead sponsor

Kutahya Health Sciences University

Other

Collaborators

  • Scientific Research Projects Coordination Unit

Registry information

Official study title

Relationship Between Pelvic Floor Muscle Activity and Voice Acoustic Parameters in Young Adults

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Aug 8, 2025
Registry last updated
Aug 8, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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