Function to calculate reaction time.

We need to extract Reaction Time data usually in milliseconds from our participants' in-scanner exp

Reaction Time for each stimulus / event refers to the brief interval of time between the start of each stimulus in the
experiment [which is logged as an individual time-stamp in the e-dat file],
and the start of the participant's vocal response to that stimulus. For each stimulus, the start of the participant's vocal response is visible as a distinct peak in the participant's sound file. Attached code working is good for single word response but fails when audio file contain more than one stimuli response.