Aditus in Audiology

In the field of audiology, the term “aditus” refers to an important anatomical structure within the ear. It describes the opening located between the pneumaticized mastoid air cells and the middle ear space. 

What does aditus mean?

In audiology, the term “aditus” refers to an opening or passageway that connects the mastoid air cells to the middle ear. It serves as a communication pathway between these two areas of the ear, allowing for the exchange of air, pressure, and sound vibrations.

What is the origin of the word aditus?

The term “aditus” originates from the Latin word “aditus,” which means “approach” or “entrance.” It accurately reflects the role of the aditus as a passage that allows access or connection between different parts of the ear.

Where is the aditus located?

The aditus is located within the temporal bone, a dense bone structure that houses the auditory system. More specifically, it is positioned at the upper posterior region of the middle ear cavity, near the epitympanic recess. The aditus connects the mastoid antrum, a cavity within the mastoid process of the temporal bone, to the middle ear space.

What is the function of the aditus in the ear?

The aditus serves several important functions within the auditory system:

  1. Ventilation and Pressure Equalization: The aditus provides a pathway for the exchange of air between the mastoid air cells and the middle ear. This allows for proper ventilation and equalization of pressure between these two spaces. When pressure imbalances occur, such as during altitude changes or Eustachian tube dysfunction, the aditus helps to maintain equilibrium and prevent discomfort or damage to the middle ear.
  1. Infection and Fluid Drainage: In cases of infection or accumulation of fluid within the mastoid air cells, the aditus plays a crucial role in draining these substances into the middle ear. This drainage mechanism helps prevent the spread of infection or fluid buildup, reducing the risk of complications such as mastoiditis or conductive hearing loss.
  1. Sound Transmission: The aditus contributes to the transmission of sound vibrations from the external environment to the middle ear. Sound waves enter the ear canal, causing the tympanic membrane (eardrum) to vibrate. These vibrations are then transmitted through the ossicles (three tiny bones in the middle ear) and eventually reach the aditus. From there, the sound energy continues its journey into the inner ear, where it is converted into electrical signals and interpreted by the brain.
  1. Surgical Access: The aditus has significance in otologic surgery. Surgeons may need to access the mastoid air cells or middle ear for various procedures, such as mastoidectomy or middle ear exploration. The aditus serves as an entry point, providing access for the surgical instruments while minimizing disruption to the delicate structures of the ear.


In audiology, the aditus refers to the opening that connects the mastoid air cells and the middle ear space. Its role in ventilation, pressure equalization, drainage, sound transmission, and surgical access highlights its importance within the auditory system. Understanding the aditus and its functions contributes to the knowledge and expertise of audiologists and healthcare professionals working with ear-related conditions.