  We review recent work aimed at showing how global topological defects
influence the shape of the angular power spectrum of the CMB radiation on small
scales. While Sachs-Wolfe fluctuations give the dominant contribution on
angular scales larger than about a few degrees, on intermediate scales the main
r\^ole is played by coherent oscillations in the baryon radiation plasma before
recombination. In standard cosmological models these oscillations lead to the
`Doppler peaks' in the angular power spectrum. Inflation-based cold dark matter
models predict the location of the first peak to be at $\ell\sim
220/\sqrt{\Omega_0}$, with a height which is a few times the level of
anisotropies at large scales. Here we focus on perturbations induced by global
textures. We find that the height of the first peak is reduced and is shifted
to $\ell\sim 350$.
