It is natural for our bodies to make undesirable sounds such as burping or passing gas. However, it is not socially acceptable to belch or pass gas in public. Those sounds should be reserved for private moments.
Occasionally, no matter how hard we try to be socially acceptable, these little sounds find a way to unexpectedly slip out. Should one of these embarrassing moments happen to you, simply say, “Excuse me.” No explanation is necessary and no response from bystanders is appropriate.