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COMMUNIKAY Vol. 8, No. 1
Acoustic Forensics Package Available Kay instrumentation and software are used for acoustic analysis by forensics specialists worldwide. Police departments, intelligence services, and private investigators have the need to analyze, edit, and enhance signals which may be a human voice or other acoustic events of interest. The Computerized Speech Lab (CSL) and several software options are the tools of choice for many of these forensic specialists requiring a highly versatile hardware/software platform. The classic spectrogram is one of the key methods for analyzing and comparing acoustic data such as voice samples. CSL provides excellent versatility with selectable sampling frequencies, multiple filter bandwidths, and adjustable dynamic range to provide the most revealing displays possible. Complementing spectrography are LPC analysis for formant extraction, fundamental frequency (with user-editable period marking when signals are noisy), spectral analysis, and more. Editing and enhancement utilities are also primary tools used by the acoustic forensics community. Very often, these specialists receive tapes which are of poor quality because they were collected amidst street noise or from a wiretapped recording. To “clean up” signals contaminated with background noise, the CSL family includes an option, Model 5142, which is a powerful editing/enhancement program designed specifically to subtract interference and noise in speech and other audio signals while maintaining the maximum possible integrity of the signal of interest. A multi-band digital equalizer, adaptive inverse filtering, and tonal noise elimination are a sampling of the enhancement capabilities provided. To obtain a product flier on the Acoustic Forensics Package, contact the company or your local representative (international customers).
Kay’s Strobe Used at Top ENT Clinics In the annual US News and World Report survey of the best hospitals and specialty departments published last year, the top 50 otolaryngology centers in the United States were listed. Among these, 43 use a Kay stroboscopy system for their voice examinations. Kay is proud to have its stroboscopy system used in the best ENT settings in the country. In addition to stroboscopy instrumentation, more than half of these departments, or their affiliated speech/voice pathology departments, own Kay acoustic analysis and/or aerodynamic instrumentation for multi-functional assessment and treatment of their patients.
Complete abstracts of these recently published studies involving Kay instrumentation can be found under Kay in the News on our Web site, www.kayelemetrics.com. Campisi, Paolo, Ted L. Tewfik, John J. Manoukian, Melvin D. Schloss, Elaine Pelland-Glais, and Nader Sadeghi. “Computer-Assisted Voice Analysis: Establishing a Pediatric Database,” Archives of Otolaryng-ology-Head and Neck Surgery, Vol. 128, pp. 156-160, Feb. 2002. Hind, Jacqueline A., Mark A. Nicosia, Ellen B. Roecker, Molly L. Carnes, and JoAnne Robbins. “Comparison of Effortful and Noneffortful Swallows in Healthy Middle-Aged and Older Adults,” Archives of Physical Medicine and Rehabilitation, Volume 82, pp. 1661-1665, December 2001. Bellandese, Mary H., Jay W. Lerman, and Harvey R. Gilbert. “An Acoustic Analysis of Excellent Female Esophageal, Tracheoesoph-ageal, and Laryngeal Speakers,” Journal of Speech, Language, and Hearing Research, Vol. 44, pp. 1315-1320, December 2001. Stager, Sheila V., Steven Bielamowicz, Ashmit Gupta, Shannon Marullo, Joan R. Regnell, and Julie Barkmeier. “Quantification of Static and Dynamic Supraglottic Activity,” Journal of Speech, Language, and Hearing Research, Vol. 44, pp. 1245-1256, Dec. 2001. Behrman, Allison, Allan L. Abramson, and David Myssiorek. “A Comparison of Radiation-induced and Presbylaryngeal Dysphonia,” Otolaryngology-Head and Neck Surgery, Volume 125, Number 3, pp. 193-200, September 2001. Roy, Nelson, Herbert A. Leeper, Michael Blomgren, and Rosalea M. Cameron. “A Description of Phonetic, Acoustic, and Physiological Changes Associated with Improved Intelligibility in a Speaker with Spastic Dysarthria,” American Journal of Speech-Language Pathology, Vol. 10, pp. 274-290, August 2001. Ertmer, David J. “Emergence of a Vowel System in a Young Cochlear Implant Recipient,” Journal of Speech, Language, and Hearing Research, Vol. 44, pp. 803-813, August 2001. Ma, Estella P-M. and Edwin M-L. Yiu. “Voice Activity and Participation Profile: Assessing the Impact of Voice Disorders on Daily Activities,” Journal of Speech, Language, and Hearing Research, Vol. 44, pp. 511-524, June 2001. Hiss, Susan G., Kathleen Treole, and Andrew Stuart. “Effects of Age, Gender, Bolus Volume, and Trial on Swallowing Apnea Duration and Swallow/Respiratory Phase Relationships of Normal Adults,” Dysphagia, Volume 16, Number 2, pp. 128-135, 2001. Woo, Peak, Adam W. Pearl, Ming-Wang Hsiung, and Peter Som. “Failed Medialization Laryngoplasty: Management by Revision Surgery,” Otolaryngology-Head and Neck Surgery, Volume 124, No. 6, June 2001. Spencer, Martin L. and Ingo R. Titze. “An Investigation of a Modal-Falsetto Register Transition Hypothesis Using Helox Gas,” Journal of Voice, Vol. 15, No. 1, pp. 15-24, March 2001. Hartel, Dana M., et al. “Objective Voice Analysis after Autologous Fat Injection for Unilateral Vocal Fold Paralysis,” Annals of Otology, Rhinology, and Laryngology, Volume 110 (3), March 2001. Robb, Michael, et al. “Acoustic Comparison of Vowel Articulation in Normal and Reverse Phonation,” JSLHR, Vol. 44, pp. 118-127, Feb. 2001. Ertmer, David J. and Jennifer A Mellon. “Beginning to Talk at 20 Months: Early Vocal Development in a Young Cochlear Implant Recipient,” JSLHR, Vol. 44, pp. 192-206, Feb. 2001. Nicosia, M. A., J. A. Hind, E. B. Roecker, M. Carnes, J. Doyle, G. A. Dengel, and J. Robbins. “Age Effects on Temporal Evolution of Isometric and Swallowing Pressure,” Journal of Gerontology - Medical Sciences, Nov. 2000. Rosen, Clark A., Lori E. Lombard, and Thomas Murray. “Acoustic, Aerodynamic, and Videostroboscopic Features of Bilateral Vocal Fold Lesions,” Annals of Otology, Rhinology, and Laryngology, Vol. 109 (9), September 2000. Wuyts, Floris L., Marc S. De Bodt, et al. “The Dysphonia Severity Index: An Objective Measure of Vocal Quality Based on a Multi- parameter Approach,” Journal of Speech, Language, and Hearing Research, Vol. 43, pp. 796-809, June 2000. Norrdzij, J. Pieter and Peak Woo. “Glottal Area Waveform Analysis of Benign Vocal Fold Lesions Before and After Surgery,” Annals of Otology, Rhinology, and Laryngology, Volume 109, pp. 441-446, May 2000. Jiang, Jack, Emily Lin, and David G. Hanson. “Acoustic and Airflow Spectral Analysis of Voice Tremor,” Journal of Speech, Language, and Hearing Research, Vol. 43, pp. 191-204, February 2000.
Q. I purchased Kay’s Nasometer II and wanted to know if the normative data published on the original Nasometer system can be applied to the new system? A. The Nasometer II design is based on the original Nasometer and uses the same innovative headset for data collection. However, the Nasometer II uses digital (as opposed to analog) filters, acquires the audio signal for playback, and works in various hardware environments (sound cards, Visi-Pitch III, and CSL) while the original system worked with dedicated hardware. Even though the original design was emulated to the extent possible in Nasometer II, preliminary investigations demonstrated some minor differences in the normative values. As a result, a new normative study is underway at the University of Texas - Austin, Department of Communication Science and Disorders. The new norms will be available this spring and posted on Kay’s Web site. Until that time, customers can interpret nasalance values on Nasometer II within the range of +/- 4 nasalance percentage points with respect to existing norms. Q.I have a Kay stroboscopy system that is 7 years old and the image is somewhat dark with flexible scopes. Can the strobe box be updated with new components or do you recommend buying a new light source? A. You may not need a new light source. Kay offers a very cost-effective upgrade to 9100 strobe boxes. The upgrade includes a new xenon bulb with approximately 30% more brightness and a significantly longer life. Additionally, a new reflector is added, the halogen motor assembly is replaced for faster switching, and other minor upgrades are included. This upgrade requires returning the strobe light source to the factory. To arrange for your upgrade, contact the service department at (973) 628-6200 ext. 159, or e-mail: service@kayelemetrics.com. Q. How can I get smaller file sizes when converting Digital Strobe footage to AVI video clips to show on laptops, PowerPoint presentations, etc.? A. Both the Digital Strobe and the Digital Swallowing Workstation have a built-in software utility for converting files to standard AVI files so they can be played on other computers, sent electronically to colleagues over the Internet, or embedded in PowerPoint presentations. These AVI files can be large in size. To reduce file size, you should first be selective about what you convert (i.e., keep length of video clip manageable). Second, use the 320x240 resolution which is adequate for most presentations. Third, check to see if “satisfactory” image quality is acceptable for your purposes. If so, this results in much smaller file size than when selecting “best” image quality by a factor of 5:1. You can go another step by converting an AVI file to an MPEG-1 file which is inherently smaller in size by a factor of nearly 10:1. Software from Ligos (www.ligos.com) can do this conversion (this software is included with new digital video systems from Kay) and there is also freeware on the Internet which can be used to make the conversion to MPEG.
What does high-speed video offer that is different from stroboscopy? In order for stroboscopy to render vocal fold motion during phonation, accurate pitch extraction is essential to determine when the strobe should flash. High Speed Video (HSV) does not require pitch extraction to show vocal fold motion. To demonstrate this point, a patient with a severely dysphonic voice (e.g., spasmodic dysphonia) is a poor candidate for stroboscopy because the highly unstable vibratory pattern of the vocal folds cannot be accurately “tracked.” HSV, on the other hand, can accurately show the actual vocal fold vibratory pattern, regardless of the patient’s voice quality, by recording some 2000 frames per second. Also, HSV shows the “start-up” of phonation when the vocal folds begin vibrating which is not seen with stroboscopy because fundamental frequency must first be detected. However, HSV still has major clinical limitations. Most importantly, the image quality is black/white and has less resolution than what is obtained with stroboscopy; this makes detection of subtle lesions problematic. Secondly, HSV requires a bright light source (300-watt xenon) at full gain used with a rigid endoscope to adequately illuminate the laryngeal area; the endoscope tip can become very hot if the patient does not tolerate scope insertion/positioning quickly. Kay offers both stroboscopy and HSV systems. Currently, HSV is used mostly by researchers to gain knowledge about vocal fold physiology not possible with stroboscopy. For now, given some of the practical limitations of HSV, stroboscopy continues to be the clinical instrument of choice for laryngeal imaging.
A new set of normative data for Kay’s acclaimed Multi-Dimensional Voice Program (MDVP) has been published in the Archives of Otolaryngology-Head and Neck Surgery (Feb. 2002) by Paolo Campisi, et al. of Montreal Children’s Hospital. Previous normative studies on MDVP have been published, but these were all on adult populations. The newly published MDVP data is unique because it pertains specifically to the pediatric population. As noted by the authors of the new study, MDVP provides an “objective, reproducible, and non-invasive measure of vocal fold function” by extracting up to 33 acoustic measurements and comparing them graphically and numerically to a built-in database. The program’s database was derived from adult speakers and the authors cite the need for having normative data for the pediatric population. The authors used 100 control subjects for the study (50 males, 50 females) to establish the new norms. Additionally, they used multilinear regression to assess associations between derived acoustic variables and the independent variables of age, sex, height, weight, and body mass index. To study the effectiveness of MDVP in detecting pathology, they also extracted acoustic parameters on 26 patients (19 males, 7 females) with vocal nodules which are a common cause of pediatric dysphonias. The normative data were then compared with the vocal profiles of the children with nodules using a retrospective, case-controlled design. Significant differences in MDVP parameters were noted between the normals and the group with nodules, especially among the frequency perturbation measurements. Clinicians who use MDVP and work with the pediatric population are encouraged to read this new study. For article reprints, contact Ted L. Tewfik, M.D., Director of Otolaryngology, The Montreal Children’s Hospital, 2300 Tupper St., Suite B240, Montreal, Quebec, Canada, H3H 1P3.
Digital Swallowing Workstation Course Kay will host a workshop on the Digital Swallowing Workstation, April 11-12, 2002, at its headquarters in Lincoln Park, NJ. The focus of the workshop, geared for beginner/intermediate-level instruction, will be on clinical applications of the workstation. Topics will include the use of surface EMG, respiration, cervical auscultation, and tongue manometry for patient treatment. Participants will have hands-on exercises with the Swallowing Signals Lab equipment. The course will also cover imaging capabilities of the system including videoendoscopy (FEES) for bedside patient assessment and fluorographic recordings. Faculty for the workshop are Michael Crary, Ph.D., and Giselle Mann, Ph.D., both of whom use the workstation clinically and have lectured widely on dysphagia. 1.3 ASHA CEUs will be offered for the course. For further information, contact Barbara Adams, (973) 628-6200 ext. 161, or e-mail: badams@kayelemetrics.com.
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