| 
        Training
            
             
              | The process of collecting speech samples for the purpose 
                  of tuning the recognition algorithm for better performance.   |   
              | There are two basic ways in which data is gathered for training. 
                One is referred to as "supervised" and the other 
                is "unsupervised". |   
              | Supervised Training  
                  Here the user is asked to say specific utterances and the 
                    samples are stored with reference to this identity. 
                     
                      | Example for Speech Verification 
                          When a speaker attempts to verify himself with this 
                            system, his incoming signal is compared to that of 
                            a "key". 
 
This key should be a signal that produces a high 
                            correlation for both magnitude and pitch data when 
                            the authorized user utters the password, but not in 
                            cases where: 
                            
                               the user says the wrong word (the password 
                                is forgotten) an intruder says either the password or a wrong 
                                word 
 
To develop such a key, the system is trained 
                            for recognition of the speaker. In this instance, 
                            the speaker first chooses a password, and it is acquired 
                            five separate times. The pitch and magnitude information 
                            are recorded for each. The signal that matches the 
                            other four signals best in both cases is chosen as 
                            the key.  |    |   
              | Unsupervised Training 
                  Here the user is asked to speek but, not given a predefined, 
                    known text reference to say. This kind of training is more 
                    challenging to use. |    |