Pathological binaural phase time delay (BPTD) asynchrony is measured at a variety of frequencies and to speech stimuli to develop a BPTD profile for a subject. Then a corrective device (600, 1000) is designed to apply clinical BPTD to compensate for the subject's pathological BPTD. An electronic device (500) is used to measure the subject's ability to comprehend words at a variety of relative time delays between ears to estimate the ideal overall relative time delay. The optimal relative phase shift at a variety of frequencies is also measured. An electronic device (600) may be used to correct the pathological BPTD by delaying sound in different frequency bands differently to the target ear, according to the BPTD profile, or a passive filtered earplug (1000) may be used to correct smaller amounts of BPTD.