SPECIFICATION SPECIFICATION A document prepared specifically to support acquisition that clearly and accurately describes essential technical requirements for purchasing materiel. Procedures necessary to determine that the requirements for the materiel covered by the specification have been met are also included. SPECIFICATION CHANGE NOTICE (SCN) A document used to propose, transmit, and record changes to a specification. SPECIFICATION CONTROL DRAWING See Vendor item drawing. SPECIFIC GRAVITY The ration of the weight of any volume of a substance to the weight of an equal volume of another substance taken as standard at a constant or stated temperature. SPEECH SIGNAL PROCESSING The modification of the elec- trical signal representing speech to enhance the capability of a speech communications channel. Some examples are simple analog processing, automatic gain control, frequency shaping, peak clip- ping, and syllabic compression.