A system for use of acoustic reflectometry in nasogastric enteral access devices, the system comprising: a nasogastric enteral access device; a sound generator to emit sound into the nasogastric enteral access device; at least one sound receiver to detect amplitudes and timings of returning acoustic reflections at a plurality positions of a distal end of the nasogastric enteral access device within a body; and a reflectometry device having at least one processor and a memory that is accessible to the processor configured to analyze amplitudes and timings of the returning acoustic reflections, characterized in that: the acoustic reflections include a first acoustic reflection of a first deformation in a wall of the nasogastric enteral access device from a first esophageal sphincter and a second acoustic reflection of a second deformation in the wall of the nasogastric enteral access device from a second esophageal sphincter, and the reflectometry device is configured to analyze the timings of the returning acoustic reflections to determine a distance the distal end of the nasogastric enteral access device is inserted past the second esophageal sphincter, and to indicate the distal end of the nasogastric enteral access device is in the stomach based on the determined distance past the second esophageal sphincter. a nasogastric enteral access device; a sound generator to emit sound into the nasogastric enteral access device; at least one sound receiver to detect amplitudes and timings of returning acoustic reflections at a plurality positions of a distal end of the nasogastric enteral access device within a body; and a reflectometry device having at least one processor and a memory that is accessible to the processor configured to analyze amplitudes and timings of the returning acoustic reflections, characterized in that: the acoustic reflections include a first acoustic reflection of a first deformation in a wall of the nasogastric enteral access device from a first esophageal sphincter and a second acoustic reflection of a second deformation in the wall of the nasogastric enteral access device from a second esophageal sphincter, and the reflectometry device is configured to analyze the timings of the returning acoustic reflections to determine a distance the distal end of the nasogastric enteral access device is inserted past the second esophageal sphincter, and to indicate the distal end of the nasogastric enteral access device is in the stomach based on the determined distance past the second esophageal sphincter. the acoustic reflections include a first acoustic reflection of a first deformation in a wall of the nasogastric enteral access device from a first esophageal sphincter and a second acoustic reflection of a second deformation in the wall of the nasogastric enteral access device from a second esophageal sphincter, and the reflectometry device is configured to analyze the timings of the returning acoustic reflections to determine a distance the distal end of the nasogastric enteral access device is inserted past the second esophageal sphincter, and to indicate the distal end of the nasogastric enteral access device is in the stomach based on the determined distance past the second esophageal sphincter.