Absorbance can be used to assess the function of the middle ear across a wide range of frequencies. This measurement has been shown to have many clinical applications in particular in the paediatric population. This study aimed to measure the rate at which functional maturation of the middle ear occurs in the first 6 months of life. A secondary aim was to use this information to establish a normative data set. The results identified that absorbance between 600 – 1600 Hz remained relatively constant across the first 6 months of life. However, at frequencies below 400 Hz, the absorbance reduced with maturation; whereas in the high frequencies (> 2000 Hz), the absorbance increased during this time period. These changes are consistent with the changes to the mass and stiffness of the middle ear as described in previous studies. Because there are significant developmental changes during this time, the authors recommend that age specific normative data is used between 0 – 6 months. Therefore when testing absorbance in the Titan it is important to ensure the correct age of the patient is selected in order to see the relevant normative data.