# Understanding Low or No Background Audio

## In brief

Goal
  Prerecorded speech is not disrupted by background sound.
What to do
  Avoid or lessen background sound, or let users turn it off.
Why it's important
  People who are hard of hearing may have difficulty distinguishing speech from music and other sounds.

## Intent of Low or No Background Audio

The intent of this Success Criterion is to ensure that any non-speech sounds are low enough that a user who is hard of hearing can separate the speech from background sounds or other noise foreground speech content.

The value of 20 dB was chosen based on Large area assistive listening systems (ALS): Review and recommendations [[LAALS]] and In-the-ear measurements of interference in hearing aids from digital wireless telephones [[HEARING-AID-INT]]

## Benefits of Low or No Background Audio

- People who are hard of hearing often have great difficulty separating speech from background sound.

## Examples of Low or No Background Audio

## Resources for Low or No Background Audio

- About Decibels

## Techniques for Low or No Background Audio

### Sufficient Techniques for Low or No Background Audio

- Mixing audio files so that non-speech sounds are at least 20 decibels lower than the speech audio content

### Additional Techniques (Advisory) for Low or No Background Audio

### Failures for Low or No Background Audio