The invention discloses a parameter self-adjusting method for a fitting-free 
hearing aid. The parameter self-adjusting method comprises the following steps: 1, determining 10 groups of parameters [a1, b1, a2, b2, r, s, t] from 1 to 10; 2, according to the 
hearing loss of the patient at the 
center frequency CF, respectively calculating the 
hearing loss of internal / external hair cells corresponding to the 10 groups of parameters, and the 
maximum gain and compensation coefficient of the normal ear and the affected ear; 3, framing and windowing the input voice xin, and calculating an 
energy spectrum E(k) of each frame of 
signal; 4, calculating compensation gains corresponding to the 10 groups of parameters; 5, enabling the compensation 
gain calculated in the step 4 to act on the 
signal spectrum, and obtaining 10 groups of compensated voice signals; and 6, calculating the fitness of the 10 groups of voice signals, and regenerating 10 groups of parameters. According to the parameter self-adjustment method for the fitting-free 
hearing aid, the 
loudness compensation model is established according to the 
cochlea hearing loss model, the parameters are adjusted adaptively based on the intelligent 
algorithm, and the method has the advantages of being good in 
loudness compensation effect and convenient to deploy.