Douglas W. Montequin

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The United States Bureau of Labor Statistics and other sources were consulted about the percentages of the working population that we identified as professional voice users. The largest percentage may be in sales and sales-related occupations (13%), but the exact breakdown of those who approach their clients vocally rather than by mail is still uncertain.(More)
High-speed digital imaging of the medial surface of the vocal folds was performed in excised canine larynx experiments. Building on the excised larynx investigations of Baer [Ph.D. dissertation, MIT, Boston, MA (1975)] and hemilarynx investigations of Jiang and Titze [Laryngoscope 103, 872-882 (1993)], nine vocal fold fleshpoints were tracked simultaneously(More)
A quantitative output-cost ratio (OCR) is proposed for objective use in voice production and is defined as the ratio of the acoustic output intensity to the collision intensity of the vocal folds. Measurement of the OCR is demonstrated in a laboratory experiment using 5 excised larynges and a transducer designed for use on human subjects. Data were gathered(More)
The pressure-flow relationship was examined in excised canine and human larynges with and without a vocal tract. Canine and human larynges were prepared and cut in the midsagittal plane from the top to about 10 mm below the vocal folds. The right half was removed and replaced with an acrylic plate. The vocal tract was simulated initially with a 15-cm(More)
The larynges of eight squirrel monkeys were harvested, dissected, mounted on a pseudotracheal tube, and phonated using compressed air. Patterns of vocal fold oscillation were compared with sound spectrograms of calls recorded from monkeys in our colony. Four different regimes of vocal fold activation were identified. Regime 1 resembled typical human vowel(More)
Vocal fold scarring remains a therapeutic challenge. Hepatocyte growth factor (HGF) has strong antifibrotic activity and has proved to have therapeutic potential in restoration of scar tissues such as liver cirrhosis and lung fibrosis. The present study aimed to clarify the effects of HGF injection into scarred vocal folds in a canine model. Canine vocal(More)
PURPOSE To develop and evaluate a rat excised larynx model for the measurement of acoustic, aerodynamic, and vocal fold vibratory changes resulting from vocal fold scar. METHOD Twenty-four 4-month-old male Sprague-Dawley rats were assigned to 1 of 4 experimental groups: chronic vocal fold scar, chronic vocal fold scar treated with 100-ng basic fibroblast(More)
To examine the functional effects of hyaluronan and collagen alterations in acute vocal fold scar, we injured 15 pig larynges by vocal fold mucosa stripping. At 3, 10, and 15 days after operation, we performed excised larynx experiments to measure phonation threshold pressure (PTP) and vocal economy (an acoustic output-cost ratio; OCR), and then performed(More)
OBJECTIVES/HYPOTHESIS Vocal fold scarring disrupts the layer structure of the vocal fold lamina propria that is essential for optimal mucosal vibration. Prevention of vocal fold scarring remains challenging. Hepatocyte growth factor (HGF) has strong antifibrotic activity. The authors' previous studies have found that HGF stimulates hyaluronic acid(More)
Rotational and translational stiffnesses were calculated for arytenoid motion about the cricoarytenoid joint. These calculations were obtained from measurements on five excised human larynxes. For each larynx, known forces were applied to the arytenoid cartilage, and three markers were tracked as a function of applied forces. Assuming rigid body motion,(More)