Interface vibrational modes localized at the apexes of pyramidal InAs self-assembled quantum dots embedded in GaAs were observed by resonance Raman scattering. The comparison of the frequency positions of the interface modes with those obtained theoretically reveals a strong influence of the strain. The strain calculated for the InAs/GaAs dots satisfactorily explains the strain-induced frequency shifts obtained for the interface modes. It is important to notice that the interface modes observed in this study can be found in any corrugated interfaces containing tips and cusps where they can be localized.