According to the legend, Postnik and Barma could not speak after constructing the cathedral.

Summary: The text mentions a legend where the architects were blinded after completing the cathedral so they could not create anything similar or equal. It does not mention them being unable to speak.

Detailed analysis: The text states, "According to one of the popular legends, the architects blinded after completed the cathedral, so that they could never create anything that was similar or equal." The legend described is about blinding, not about losing the ability to speak.

Conclusion: This statement is FALSE based on the provided text.