To cancel the lower-frequency portions of the noise, noise-cancelling headphones use active noise control. They incorporate a microphone that measures ambient sound, generate a waveform that is the exact negative of the ambient sound, and mix it with any audio signal the listener desires.
Esophageal hiatus. In human anatomy, the esophageal hiatus is an opening in the diaphragm through which the esophagus and the vagus nerve pass. It is located in the right crus, one of the two tendinous structures that connect the diaphragm to the spine. Fibers of the right crus cross one another below the hiatus.
GI Blockage Diagram. The esophagus is the long, narrow food tube that carries food and liquid from the mouth to the stomach. It can become blocked or injured in a variety of ways. Esophageal dilatation is the technique used to stretch or open the blocked portion of the esophagus.I Blockage Diagram. The esophagus is the long, narrow food tube that carries food and liquid from the mouth to the stomach. It can become blocked or injured in a variety of ways. Esophageal dilatation is the technique used to stretch or open the blocked portion of the esophagus.