The frequency subband scale-factors are fundamental components of MPEG-1 audio encoded bitstreams. Examination of scale-factor weights is sufficient for the establishment of an audio amplitude profile of an audio track. If, for sports programme TV broadcasts, the audio amplitude is assumed to primarily reflect the noise level exhibited by the commentator (and/or attending spectators), then, this vocal reaction to the significance of unfolding events may be used as a basis for summarisation. i.e. by relying on the exhilaration, or otherwise, expressed by the commentator/spectators, individual clips of the programme (e.g. camera shots), may be ranked according to their relative significance. A summary may then be produced by amalgamating (chronologically) any number of these clips corresponding to selected audio peaks.