A computer-implemented method, system, and/or computer program product recognizes a voice input received by an interactive voice recognition system. An unintelligible voice input is received from a caller. The unintelligible voice input is unintelligible to a computer due to background noise at a caller environment of the caller. Upon determining that the unintelligible voice input does not match any entry from a lexicon of known voice inputs, the caller is prompted to transmit a non-verbal electronic input to clarify the unintelligible voice input. This non-verbal electronic input is used to match the unintelligible voice input with a specific known voice input from the lexicon of known voice inputs, which is updated with the unintelligible voice input. The updated lexicon is subsequently used in future phone calls from the user to match the unintelligible voice input to the user-requested activity for the caller.