Sources Of Water Pollution. 1  Dumping of industrial wastes, containing heavy metals, harmful chemicals, by-products, organic toxins and oils, into the nearby source of water is one of the visible causes of water pollution.  Another cause for the contamination of water is the improper disposal of human and animal wastes.
Also see audio noise. Noise is unwanted electrical or electromagnetic energy that degrades the quality of signals and data. Noise occurs in digital and analog systems, and can affect files and communications of all types, including text, programs, images, audio, and telemetry.
(August 2016) (Learn how and when to remove this template message) In acoustics and specifically in acoustical engineering, background noise or ambient noise is any sound other than the sound being monitored (primary sound). Background noise is a form of noise pollution or interference. Background noise is an important concept in setting noise regulations. See noise criteria for cinema/home cinema applications.