A　hearing　aid　on-chip　system　based　on　accuracy　optimized　front-　and　back-end　blocks　is　presented　for　enhancing　the　signal　processing　accuracy　of　the　hearing　aid.　Compared　with　the　conventional　system,　the　accuracy　optimized　system　is　characterized　by　the　dual　feedback　network　and　the　gain　compensation　technique　used　in　the　front-　and　back-end　blocks,　respectively,　so　as　to　alleviate　the　nonlinearity　distortion　caused　by　the　output　swing.　By　using　the　technique,　the　accuracy　of　the　whole　hearing　aid　system　can　be　significantly　improved.　The　prototype　chip　has　been　designed　with　a　0.13　μm　standard　CMOS　process　and　tested　with　1　V　supply　voltage.　The　measurement　results　show　that,　for　driving　a　16　Ω　loudspeaker　with　a　normalized　output　level　of　300　mVp-p,　the　total　harmonic　distortion　reached　about　-60　dB,　achieving　at　least　three　times　reduction　compared　to　the　previously　reported　works.　In　addition,　the　typical　input　referred　noise　is　only　about　5　μVrms.　©　2014　Chinese　Institute　of　Electronics.