Certain oscillatory features in the primordial scalar power spectrum are known to provide a better fit to the outliers in the cosmic microwave background data near the multipole moments of \ell = 22 and 40 .
These features are usually generated by introducing a step in the popular , quadratic potential describing the canonical scalar field .
Such a model will be ruled out , if the tensors remain undetected at a level corresponding to a tensor-to-scalar ratio of , say , r \simeq 0.1 .
In this work , in addition to the popular quadratic potential , we investigate the effects of the step in a small field model and a tachyon model .
With possible applications to future datasets ( such as PLANCK ) in mind , we evaluate the tensor power spectrum exactly , and include its contribution in our analysis .
We compare the models with the WMAP ( five as well as seven-year ) , the QUaD and the ACBAR data .
As expected , a step at a particular location and of a suitable magnitude and width is found to improve the fit to the outliers ( near \ell = 22 and 40 ) in all these cases .
We point out that , if the tensors prove to be small ( say , r \lesssim 0.01 ) , the quadratic potential and the tachyon model will cease to be viable , and more attention will need to be paid to examples such as the small field models .