A method of assessing a degree of asynchronous sensory perception experienced by a subject, the method comprising the steps of: (i) exposing a subject to a first sensory stimulus and a second different sensory stimulus, wherein said first and second stimuli are presented to the subject synchronously or asynchronously (ii) querying the subject to elicit a response that indicates how well the first and second stimuli have been integrated, and recording in a data file - for each set of stimuli the subject is exposed to - the subjects response to the query together with data identifying the stimuli that were presented to the subject and the degree of any asynchrony in the presentation of the stimuli to the subject (iii) repeating steps (i) and (ii) so that the subject is exposed to a plurality of sets of stimuli, and (iv) processing said data file to determine a measure of the particular degree of sensory asynchrony experienced by said subject. Embodiments include a hearing aid calibrated for a subject with a particular degree of auditory sensory asynchrony. Examples of types of sensory stimulus for use with the method include auditory, visual, tactile or haptic stimuli.
