Methods and apparatus for operating on a non-text (voice or fax) message include for each of a number of voice messages, searching each voice message for signal samples having one of a plurality of sets of pre-defined characteristics (such as any seven or ten digit number which is then assumed to be a telephone number) as diclosed. For each signal sample found to have one of the sets of pre-defined characteristics, the found signal sample is associated with an equivalent text string and this text string is stored in an envelope for the message. Based on a user input, the messages may be searched for a given text string and on finding a message envelope containing the given text string, such message may be operated upon.
Other modifications in accordance with the scope of the invention will be apparent to those skilled in the art.