Special tests like SISI (Short Increment Sensitivity Index), TDT (Threshold Determination Test), and ABLB (Alternate Binaural Loudness Balance) are advanced diagnostic tools used to assess hearing capabilities and auditory processing. SISI measures the ability to detect small changes in sound intensity, TDT determines the lowest level at which a person can hear a tone, and ABLB evaluates loudness perception in each ear. These tests help refine hearing diagnoses and tailor personalized treatment plans for better hearing outcomes.