The correct abbreviation when referring to both ears is au.
In medical terminology, abbreviations are often used to describe the location or type of treatment. Here’s a brief explanation of the abbreviations:
- ac: This stands for ante cibum, which means before meals. It is not related to ears.
- as: This stands for auris sinistra, which means left ear.
- ad: This stands for auris dextra, which means right ear.
- au: This stands for auris utraque, which means both ears.
Therefore, when referring to both ears, the correct abbreviation is au.