Any unwanted sound in the environment that may interfere with listening depending on the speech-to-noise ratio. Background noise can include television, radio, traffic noise, fan noise, or other people talking.
Any of these noises in the environment can mask over a speech message. Advances in digital hearing aids attempt to pull the speech signal out of the surrounding background noise for better speech understanding. Unfortunately, background noise continues to be one of the major issues with people wearing hearing devices such as hearing aids or cochlear implants.