The receiver (also called "Handset") is an electroacoustic device that converts audio electrical signals into sound signals without sound leakage. It is widely used in communication terminal devices, such as mobile phones and fixed phones, to realize audio (e.g. voice, music) playback. Its quality directly affects the sound quality of calls and the human ear. Exposure to a noisy environment for a long period of time is very harmful to the human ear, so people have more stringent requirements for the receiver quality. For the single receiver test, it is necessary to accurately test the effect of the receiver on the human ear. The receiver test solution provided by CRYSOUND uses a high-leak ear simulator to test, which can authentically restore the true working characteristics of the receiver and fully meet the customer's requirements for product test performance. (High-leak ear simulator is subject to ITU-T Rec.P.57.)