Abstract: A programmable customized universal digital listening system is provided with one or more digital signal processor chips which are implemented as one or more digital filters whose parameters are established by one or more erasable programmable read-only memories (EPROMs). The information included in the EPROMs directed to the parameters of the digital filters are determined based upon the user's response to various audio signals provided from an audiologist. Based upon these responses, the EPROMs are programmed. Additionally, this listening system is provided with an additional digital filter which changes its responses based upon the frequency of any background noise.