Isolate a period of a sound

Hey, I have an array of over 100K values from a wavread audio file with a pretty high sampling rate. It is the sound of a dog barking 4 times. I would like to isolate 1 bark. I've tried filtering the data so that everything beneath a signal value of 0.05 goes to 0 and everything above goes to 1. It looks like a step function, except for the fact that there are values in between that are also 0. I would like to just isolate 1 period, but I don't know how to get the indices of the FINAL drop from 1 to 0. ... not the ones in the middle.

Here's what I've tried, thanks in advance!:

%% read in the file and isolate 1 sound [Y, FS] = wavread('Bark');

%% Isolate one sound period Yabs = abs(Y); % absolute value of signal figure(999);plot(Yabs) %visualize for n = 1:length(Yabs); if Yabs(n) > 0.05; Yabs(n) = 1; else Yabs(n) = 0; %filter low signal end end

figure(888); plot(Yabs); %visualize filtered signal

% tol = 50; % for n = 1:length(Yabs-tol) % if Yabs(n+tol)-Yabs(n) == 1 % indstart = n-750; % -750 to grab the rest of the signal beneath the threshold % end % if Yabs(n+tol)-Yabs(n) == -1 % indend = n+tol; % break % end % end

Period = [indstart, indend]

Ysolo = Y(Period(1):Period(2));

% Ysolo is the isolated period.