Word Prediction in Matlab?

Hello I have a tricky situation ?

1. I need to develop a code which can record user voice and play back?-> the code is ready and running fine.
2. Now the real problem, I need to identify the position of the spoken word.

In detail: say for example i have defined 5 seconds time duration for recording. during this time i speak a sentence "how are you ", say this whole sentence completes in 3 seconds (ideally) and the remaining 2 seconds are vacant and there are no information available.

Now, I have plotted the recorded file also. now i need to determine the position of either of the three words, that is the location of the words in whole 5 seconds duration?

could you please help me in determining code?

Answer 1

[Luke Halberstadt]

Assuming that the sound amplitude is lower when the words are not being spoken, the following solution should roughly give you a start and end time:

1. Compute the average amplitude for each of fifty 0.1 second snippets of the five seconds
2. Iterate from each end of the clip until a given number of snippets have amplitude greater than some threshold.
3. Tune (a) the number of high-amplitude snippets required to trigger the beginning and end of the audio and (b) the threshold amplitude to achieve your desired accuracy.

[Vivek Sharma]

could you please help me in writing the syntax, running out if clues :(