{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,5]],"date-time":"2025-12-05T19:24:44Z","timestamp":1764962684429,"version":"3.46.0"},"reference-count":29,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2025,12,4]],"date-time":"2025-12-04T00:00:00Z","timestamp":1764806400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>(1) Background: Non-invasive instrumental measurement of swallowing acoustic signals has rested upon the assumptions of signal symmetry and reproducibility along the cervical region and has hence taken the form of single-point acquisition on optimal sites. This study aimed to (i) revisit such assumptions by adopting a conformal array of accelerometers, and hence (ii) lay the foundation for the future design of swallowing accelerometry. (2) Methods: Thirteen young healthy individuals, including eight females (mean age \u00b1 SD = 24.38 \u00b1 0.92) and five males (mean age \u00b1 SD = 24 \u00b1 3.74), were recruited. Swallowing mechano-acoustic signals of repeated swallowing trials were captured using conformal swallowing accelerometry. The peak intensities and frequencies as well as their respective peak times were extracted from six symmetrical and vertically aligned sites. (3) Results: Three-way ANOVAs with repeated measures suggested differences across trials and channels for both peak intensity and frequency. The additional interaction of bolus volume and repeated trials with a small effect size was also indicated in peak frequency. Intra-personal variability was indicated by coefficients of variance of the peak intensity and frequency of higher than 20%, with values varying within the 95% limits of agreement of at least 10 m\/s2 and 100 Hz, respectively. However, intra-trial comparisons of contra-lateral peak intensity and frequency also revealed a high degree of variability, with the 95% limits of agreement up to 12 m\/s2 and 240 Hz, respectively. On the other hand, the time points of intra-trial peak intensity and frequency showed a high degree agreement, suggesting the possibility of signal asymmetry. (4) Conclusions: The current findings not only confirmed the previous proposal of intra-personal variability but also demonstrated preliminary counterevidence to the longstanding assumption of signal symmetry. Alternatively, the use of conformal swallowing accelerometry is a promising option for the future design and implementation of non-invasive swallowing mechano-acoustic measurements.<\/jats:p>","DOI":"10.3390\/s25237396","type":"journal-article","created":{"date-parts":[[2025,12,5]],"date-time":"2025-12-05T18:42:02Z","timestamp":1764960122000},"page":"7396","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Conformal Swallowing Accelerometry: Reimagining the Acquisition and Characterization of Swallowing Mechano-Acoustic Signals"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8932-0312","authenticated-orcid":false,"given":"Wilson Yiu Shun","family":"Lam","sequence":"first","affiliation":[{"name":"Department of Language Science and Technology, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"},{"name":"Research Institute for Smart Ageing, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9681-6201","authenticated-orcid":false,"given":"Elaine","family":"Kwong","sequence":"additional","affiliation":[{"name":"Department of Language Science and Technology, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"},{"name":"Research Institute for Smart Ageing, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4316-2590","authenticated-orcid":false,"given":"Randolph Chi Kin","family":"Leung","sequence":"additional","affiliation":[{"name":"Research Institute for Smart Ageing, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"},{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chak Hang","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Language Science and Technology, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-5859-5269","authenticated-orcid":false,"given":"Sanjaya","family":"Rai","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Leo Kwan","family":"Lui","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1007\/BF00341261","article-title":"Symmetry and reproducibility of swallowing sounds","volume":"9","author":"Takahashi","year":"1994","journal-title":"Dysphagia"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1007\/BF00262760","article-title":"Methodology for detecting swallowing sounds","volume":"9","author":"Takahashi","year":"1994","journal-title":"Dysphagia"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1007\/s00455-001-0100-x","article-title":"Detection of Swallowing Sounds: Methodology Revisited","volume":"17","author":"Cichero","year":"2002","journal-title":"Dysphagia"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1044\/nsshla_12_38","article-title":"Evaluation and treatment of swallowing disorders","volume":"12","author":"Logemann","year":"1984","journal-title":"NSSLHA J."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1007\/PL00009548","article-title":"The Physiologic Cause of Swallowing Sounds: Answers from Heart Sounds and Vocal Tract Acoustics","volume":"13","author":"Cichero","year":"1998","journal-title":"Dysphagia"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1038\/s41551-019-0480-6","article-title":"Mechano-acoustic sensing of physiological processes and body motions via a soft wireless device placed at the suprasternal notch","volume":"4","author":"Lee","year":"2019","journal-title":"Nat. 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