Acoustic therapy is one of the most important therapeutic tools to achieve responsive adaptation to tinnitus. The so-called responsive adaptation means that although the patient “hears” tinnitus, it no longer poses any impact on daily life and no longer brings discomfort such as distress, thus achieving complete adaptation to tinnitus. Currently, there are two main strategies used in acoustic therapy, namely the semi-masking strategy and the masking strategy. This is a commonly used approach and is recognized as the more effective method in tinnitus treatment at present. When masking sound is applied to the tinnitus affected ear, the “compensatory” activity of the outer hair cells outside the cochlear lesion area is inhibited, thus reducing tinnitus. Psychologically speaking, tinnitus patients feel happier with the masking sound than with their own tinnitus. The size, frequency and whether to listen to the masking sound from the masking device can be adjusted by the patients themselves. The purpose is to suppress the spontaneous excitatory activity of the cochlea or auditory nerve by using external sound. The mechanism may be to inhibit the central auditory pathway above the lesion, thus reducing or inhibiting the perception of tinnitus. (1) Indications: Long-term, severe tinnitus; tinnitus of unknown etiology; tinnitus of clear etiology but untreated for a long time, used while actively treating the primary cause; tinnitus remaining after the etiology is cured, such as tinnitus after sudden deafness is cured. (2) Contraindications: No absolute contraindications; relative contraindications include: auditory allergy, psychiatric diseases with clear diagnosis but uncontrolled symptoms, patients with severe hypertension, diabetes, cardiovascular diseases. However, masking treatment can still be performed after the underlying diseases mentioned above have been controlled.