{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T04:31:59Z","timestamp":1777869119485,"version":"3.51.4"},"reference-count":0,"publisher":"S. Karger AG","license":[{"start":{"date-parts":[[2009,12,9]],"date-time":"2009-12-09T00:00:00Z","timestamp":1260316800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"},{"start":{"date-parts":[[2009,12,9]],"date-time":"2009-12-09T00:00:00Z","timestamp":1260316800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Folia Phoniatr Logop"],"abstract":"<jats:p>The effects of prolonged (5 \u00d7 45 min) reading in different environmental and ergonomic conditions on time-based glottal waveform parameters of normal female and male subjects (n = 80) were studied. The exposure groups (n = 5 females and males per cell) consisted of eight combinations of the following factors: (1) normal ( &lt; 65 dB) or high ( &gt; 65 dB) speech output level; (2) sitting or standing posture; (3) low (25 \u00b1 5%) or high (65 \u00b1 5%) relative humidity of ambient air. Two rest (morning and noon) and three loading (two in the morning and one in the afternoon) samples were recorded and analyzed. The glottal waveforms were obtained by inverse filtering of the acoustical signal using an automatic method. The following time-based parameters were analyzed from the estimated glottal now waveform: (1) length of fundamental period; (2) open quotient; (3) speed quotient, and (4) closing quotient. The analysis was based on inverse filtering of the first stressed syllable of \u2018paappa\u2019 words repeated 3x5 times with normal, maximally soft and maximally loud phonation. Humidity was a significant factor in serveral instances. The interactions between gender and the loading factors were striking.<\/jats:p>","DOI":"10.1159\/000266463","type":"journal-article","created":{"date-parts":[[2009,12,10]],"date-time":"2009-12-10T02:56:10Z","timestamp":1260413770000},"page":"247-263","source":"Crossref","is-referenced-by-count":25,"title":["Loading Changes in Time-Based Parameters of Glottal Flow Waveforms in Different Ergonomic Conditions"],"prefix":"10.1159","author":[{"given":"Erkki","family":"Vilkmari","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eija-Riitta","family":"Lauri","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paavo","family":"Alku","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eeva","family":"Sala","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marketta","family":"Sihvo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2009,12,9]]},"container-title":["Folia Phoniatrica et Logopaedica"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/karger.com\/article-pdf\/doi\/10.1159\/000266463","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T13:10:29Z","timestamp":1777554629000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000266463"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,12,9]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1159\/000266463","archive":["Portico"],"relation":{},"ISSN":["1021-7762","1421-9972"],"issn-type":[{"value":"1021-7762","type":"print"},{"value":"1421-9972","type":"electronic"}],"subject":[],"published":{"date-parts":[[2009,12,9]]}}}