Ferroelectric microregions and Raman scattering in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">KTaO</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Raman spectra of both nominally pure and deliberately doped ${\mathrm{KTaO}}_{3}$ are presented which support the view that symmetry-breaking defects induce ferroelectric microregions even far above the bulk ${T}_{c}$ which grow dramatically as temperature is lowered. A characteristic size of these regions is extracted from an analysis of the spectra. The value of ${R}_{0}$/a varies from nearly 4 at low temperatures to about 1.3 at 100 K, the highest temperature where it was determined. For a mixed crystal long-range order sets in when these regions become sufficiently large so as to occupy the major fraction of the sample's volume. We also find evidence of such regions even in nominally pure ${\mathrm{KTaO}}_{3}$, thus implicating very dilute symmetry-breaking defects of unknown chemical composition, or intrinsic localized fluctuations.