Background noise in DNA sequencing refers to unwanted signals or errors that occur during the sequencing process, which can interfere with the accurate interpretation of the data. It appears as numerous smaller, undefined peaks under your sequence peaks of interest. 

Background noise can arise from various sources, such as contamination, low DNA, or non-specific binding of sequences. If the noises are too strong, the software may not be able to resolve base peaks from background noise, making it difficult to distinguish true genetic signals from artifacts. This could lead to potential inaccuracies in the results.

While background noises are always present, they can be rendered undetectably by using well-prepared samples of good signal strength.