Two Artin algebras \(\Lambda\) and \(R\) over a commutative Artin ring \(k\) are called right socle equivalent, if the factor algebras \(\Lambda/\text{soc}(\Lambda_\Lambda)\) and \(R/\text{soc}(R_R)\) are isomorphic. The paper deals with the question when a self-injective algebra \(A\) is socle equivalent to a split-extension algebra of an algebra \(B\), without oriented cycles in its ordinary quiver, by a \(B\)-bimodule. The authors introduce the notion of a deforming ideal of a self-injective algebra, investigate general properties of such ideals and exhibit their importance for the representation theory of self-injective Artin algebras.