8. In a speech analysis system in which an audio signal is spectrum analyzed for recognizing at least one predetermined keyword in a continuous audio signal, each said keyword being characterized by a template having at least one target pattern representing a plurality of short-term power spectra spaced apart in real time, an analysis method comprising the steps of repeatedly evaluating electrical signals representing a set of parameters determining a short-term power spectrum of said audio signal within each of a plurality of equal duration sampling intervals thereby to generate an uninterrupted time-ordered sequence of short-term audio power spectrum frames, repeatedly selecting from said sequence of frames, one first frame and at least one later occurring frame to form a multi-frame pattern, comparing each thus formed multi-frame pattern with each first target pattern of each keyword template, deciding whether each said multi-frame pattern corresponds to a first target pattern of a keyword template, for each multi-frame pattern which, according to said deciding step, corresponds to a said first target pattern of a potential candidate keyword, selecting later occurring short-term power spectra to form later occurring multi-frame patterns, deciding whether said later occurring multi-frame patterns correspond respectively to successive target patterns of said potential candidate keyword template, identifying electrical signals representing a candidate keyword template when said selected multi-frame patterns correspond respectively to the target patterns of a said keyword template, normalizing electrical signals representing the time duration spacings between multi-frame patterns corresponding to said candidate word, and applying a prosodic test to said normalized time duration spacings, wherein said normalized time duration spacings for a candidate word must meet the timing criteria imposed by said prosodic test before a said candidate word is accepted as a recognized keyword.
9. The method of claim 8 wherein said applying step comprises the step of applying fixed, predetermined spacing limits to each normalized spacing, whereby said normalized spacings must fall within said fixed time limits before said candidate word is accepted.