A defect detection method for detecting a defect in an object, wherein the method comprises: obtaining ultrasound scan data derived from an ultrasound scan of the object under consideration, the ultrasound scan data being in the form of a set of echo amplitude values representing the amplitude of echoes received from the object during ultrasound scanning at certain spatial and temporal points; processing the ultrasound scan data to remove echo amplitude values received after a predetermined threshold time; generating at least one image from the processed ultrasound scan data; subjecting each generated image to an automated defect recognition process to determine whether there is a defect in the portion of the object represented by the image; issuing a notification indicating whether or not a defect has been found; and if a defect has been found, storing the result of the automated defect recognition process in a defect database; characterised in that: the method further comprises, before the processing of the ultrasound scan data, dividing the set of echo amplitude values into a plurality of sub-sets and determining the value of the threshold time, wherein determining the value of the threshold time comprises: for each sub-set, deriving from the amplitude values in the sub-set a vector representing the amplitude values for each time point in the sub-set; identifying in each vector the end time point corresponding to the largest sequence of positive amplitude values; and selecting, from amongst all the end time points identified for the vectors, the end time point with the greatest value, or a value calculated using that end time point, as the value of the predetermined threshold time; wherein processing the ultrasound scan data includes removing the echo amplitude values received after the predetermined threshold time from each subset. obtaining ultrasound scan data derived from an ultrasound scan of the object under consideration, the ultrasound scan data being in the form of a set of echo amplitude values representing the amplitude of echoes received from the object during ultrasound scanning at certain spatial and temporal points; processing the ultrasound scan data to remove echo amplitude values received after a predetermined threshold time; generating at least one image from the processed ultrasound scan data; subjecting each generated image to an automated defect recognition process to determine whether there is a defect in the portion of the object represented by the image; issuing a notification indicating whether or not a defect has been found; and if a defect has been found, storing the result of the automated defect recognition process in a defect database; characterised in that: the method further comprises, before the processing of the ultrasound scan data, dividing the set of echo amplitude values into a plurality of sub-sets and determining the value of the threshold time, wherein determining the value of the threshold time comprises: for each sub-set, deriving from the amplitude values in the sub-set a vector representing the amplitude values for each time point in the sub-set; identifying in each vector the end time point corresponding to the largest sequence of positive amplitude values; and selecting, from amongst all the end time points identified for the vectors, the end time point with the greatest value, or a value calculated using that end time point, as the value of the predetermined threshold time; wherein processing the ultrasound scan data includes removing the echo amplitude values received after the predetermined threshold time from each subset. the method further comprises, before the processing of the ultrasound scan data, dividing the set of echo amplitude values into a plurality of sub-sets and determining the value of the threshold time, wherein determining the value of the threshold time comprises: for each sub-set, deriving from the amplitude values in the sub-set a vector representing the amplitude values for each time point in the sub-set; identifying in each vector the end time point corresponding to the largest sequence of positive amplitude values; and selecting, from amongst all the end time points identified for the vectors, the end time point with the greatest value, or a value calculated using that end time point, as the value of the predetermined threshold time; for each sub-set, deriving from the amplitude values in the sub-set a vector representing the amplitude values for each time point in the sub-set; identifying in each vector the end time point corresponding to the largest sequence of positive amplitude values; and selecting, from amongst all the end time points identified for the vectors, the end time point with the greatest value, or a value calculated using that end time point, as the value of the predetermined threshold time; wherein processing the ultrasound scan data includes removing the echo amplitude values received after the predetermined threshold time from each subset.