Janice B Chapman

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OBJECTIVES The prevalence of cholelithiasis has been established in population-based surveys employing ultrasonography, and major risk factors have been identified. However, the clinical and epidemiological features that distinguish patients with pigment gallstones from those with cholesterol stones have received little attention. METHODS We prospectively(More)
In this study, members of a professional opera chorus were recorded using close microphones, while singing in both choral and solo modes. The analysis included computation of long-term average spectra (LTAS) for the two song sections performed and calculation of singing power ratio (SPR) and energy ratio (ER), which provide an indication of the relative(More)
Recordings of the rib cage and abdominal motions and acoustic output were obtained from five professional opera singers during performance of an aria recorded with two levels of voice projection. The condition of greater projection resulted in a significant increase in the acoustic power in the frequency band 2-4 kHz, relative to the power in the 0-2 kHz(More)
Operatic sopranos need to be audible over an orchestra yet they are not considered to possess a singer's formant. As in other voice types, some singers are more successful than others at being heard and so this work investigated the frequency range of the singer's formant between 2000 and 4000 Hz to consider the question of extra energy in this range. Such(More)
INTRODUCTION The MTI photoscreener (MTI) and the Welch-Allyn SureSight autorefractor are commonly used for preschool vision screening. We compared both of these methods on 100 consecutive patients in a prospective, randomized, masked, clinical trial conducted at a tertiary care center. METHODS One hundred patients between 1 and 6 years of age were(More)
Criteria for determining the classification of singers in research has posed numerous problems for both researchers and their readership. Previous attempts at creating usable categories have failed because of disagreement within the professions involved in such research. The object of this paper is to explore and suggest a system in which scientific(More)
Although considerable progress has been made in the development of acoustic and physiological measures of operatic singing voice, there is still no widely accepted objective tool for the evaluation of its multidimensional features. Auditory-perceptual evaluation, therefore, remains an important evaluation method for singing pedagogues, voice scientists, and(More)
BACKGROUND The treatment of patients with gallstones who have suffered a first episode of acute biliary pain is controversial. Recent guidelines suggest that such patients may choose to observe the "pattern" of their pain over time before deciding about therapy. OBJECTIVE To determine clinical factors that would identify patients at high risk for 2(More)