1 The water table forms the top of the zone of saturation, where pore spaces in sediment or rock are completely filled with water. 2  Aquifers are underground areas of sediment or rock that hold groundwater. 3  In steep areas, where groundwater intersects the ground surface, a spring or seep can form.
There's a word for what you're asking for-- onomatopoeia. Many times editors would rather you not use the sounds, but describe it, unless you're writing a PB or even early chapter book. I wrote about a train in one of my short stories. As a train gets closer, it makes a rumbling sound. As it leaves the station, it makes a steadily increasing chugging sound. The whistle sounds like a forlorn call in the night. The brakes hiss and screech when the train slows down to a stop. If you don't have a train nearby to listen to, go online and do a search.
Heart sounds are the noises generated by the beating heart and the resultant flow of blood through it. Specifically, the sounds reflect the turbulence created when the heart valves snap shut. In cardiac auscultation, an examiner may use a stethoscope to listen for these unique and distinct sounds that provide important auditory data regarding the condition of the heart. In healthy adults, there are two normal heart sounds often described as a lub and a dub, that occur in sequence with each heart