Issue Navigator

Volume 14 No. 10
Earn CME
Accepted Papers

Scientific Investigations

Effects of Increased Pharyngeal Tissue Mass Due to Fluid Accumulation in the Neck on the Acoustic Features of Snoring Sounds in Men

Shumit Saha, MSc1,2,5; Zahra Moussavi, PhD1; Peyman Hadi, MSc3; T. Douglas Bradley, MD2,4; Azadeh Yadollahi, PhD2,5
1Department of Biomedical Engineering, University of Manitoba, Winnipeg, Manitoba, Canada; 2Toronto Rehabilitation Institute-University Health Network, Toronto, Ontario, Canada; 3BresoTec Inc., Toronto, Ontario, Canada; 4Department of Medicine, University of Toronto, Toronto, Ontario, Canada; 5Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada

Study Objectives:

Snoring sounds are generated by the vibration of pharyngeal tissue due to the upper airway narrowing. While recorded by a microphone placed over the neck, snoring can pass through the pharyngeal tissue surrounding the upper airway. Thus, changes in the pharyngeal tissue content may change the acoustic properties of the snoring sounds. Rostral fluid shift and the consequent increases in neck fluid volume (NFV) and neck circumference (NC) can increase pharyngeal tissue mass. Therefore, the goal of this study was to investigate the relationship between increases in pharyngeal tissue mass, as assessed by increased NFV and NC, and snoring sounds features.


We obtained data from a previous study where 20 males who were not obese participated in a daytime polysomnography and their NC and NFV were measured before and after sleep. During sleep, snoring sounds were recorded with a microphone placed over the neck. Spectral centroid of the snoring sounds was estimated. Then, the first five snoring segments were selected from the first and last 30 minutes of stage N2 sleep.


We found a significant decrease in the snoring spectral centroid from the beginning to end of sleep. We also found that spectral centroid from the end of sleep in frequency ranges below 200 Hz was inversely correlated with the increases in NFV and NC from before to after sleep.


These results suggest that snoring spectral centroid can be used as a noninvasive and convenient method to assess variations in the pharyngeal tissue mass.


Saha S, Moussavi Z, Hadi P, Bradley TD, Yadollahi A. Effects of increased pharyngeal tissue mass due to fluid accumulation in the neck on the acoustic features of snoring sounds in men. J Clin Sleep Med. 2018;14(10):1653–1660.

Please login to continue reading the full article

Subscribers to JCSM get full access to current and past issues of the JCSM.

Login to JCSM

Not a subscriber?

Join the American Academy of Sleep Medicine and receive a subscription to JCSM with your membership

Subscribe to JCSM:  $75/volume year for individuals or $140/volume year for institutions to access all current articles and archives published in JCSM.

Download this article*:   $20 to access a PDF version of a specific article from the current issue of JCSM.

*Purchase of an electronic download of JCSM provides permission to access and print the issue/article for personal scholarly, research and educational use. Please note: access to the article is from the computer on which the article is purchased ONLY. Purchase of the article does not permit distribution, electronic or otherwise, of the article without the written permission of the AASM. Further, purchase does not permit the posting of article text on an online forum or website.