Playing a sound and then stopping it

Hello everybody ! I am new to Matlab, but i tried some things out and it is really nice. But now to my question. I am generating a sine by playing it through the function sound. While i am generating a sine, the ampltidue is increasing. This means, we perceive the sound louder over time. The duration is about 20 seconds. Now i want to play the sound and then , for example, stop it at 5 seconds. Is it possible ? I (Btw english is not my mother language, sry about that...)

 fs=44100;   %Sample Frequency
 samples=1/fs;
 d=20;        %Duration
 t=0:samples:(d-samples); % time
 amp=linspace(0.0001,2,882000); %Increasing the amplitude

 input('Please press enter to go on ')

 a = true; 
 while a

 disp('') 
 Enter = input('Chose 1 and press enter to play sound: ');

   switch Enter
      case 1 %Generating sound with a frequency of 125 Hz          
          f = 125;
          s1 = sin(2*pi*f*t);
          y= amp.*s1;
          sound(y,fs);

   end     
end