The Utility of Cervical Auscultation in the Evaluation of Dysphagia

As the curtains of the dark ages parted there was newly inspired interest in science and medicine. The 1600–1800s proved to be a remarkable era of technological development. In a span of only 100 years, the thermometer, microscope, and instrumentation for the measurement of blood pressure and respiration came into being (Trefil, 2001). Equally important was the discovery in 1791 by Austrian physician Leopold Auenbrugger that “percussing” (tapping) on various locations on the chest and abdomen would yield acoustic information that was of diagnostic value (Steudel, 1970). While this was a seminal finding, it remained for French physician Dr. R.T.H. Laennec to develop the necessary instrumentation for widespread use of the technique. It was in 1816 that Laennec first rolled up a tube of paper and held one end to a patient’s chest nd the other to his ear (Sakula, 1981). Appreciating the sounds he heard, Laennec then developed a series of devices now known as stethoscopes. The technique Laen-nec developed is “auscultation” and is defined as: “The act of listening for sounds arising within organs (as the lungs or heart) as an aid to diagnosis and treatment, the examination being made either by use of the stethoscope or by direct application of the ear to the body” (Gove, 1981, p. 145). While this classical definition of auscultation has been adequate in the past, it does not reflect the applications made possible by current developments in signal processing technology. Consequently, for the purposes of this article, I will broaden the definition to include the gathering and interpretation of acoustic information that may be made possible, not just through a stethoscope or the naked ear, but also through microphones, accelerometers, and electronic signal processing devices.