3.  Sound effects  Our project  Background & techniques  Applications  Methodology  Results  Conclusion

4.  artificially created or enhanced sounds › Delay › Multiple Echo › All pass Reverberation › A Natural Sounding Reverberation › Flanging › Equalizer

5.  plays audio after the delay time  from several milliseconds to several seconds  Analog delay  Digital delay  is used by electric guitarists

6.  Reflection of sound  infinite number of echoes  in music may produce unpleasant effect

7.  result of the many reflections of a sound  sound source stops but the reflections continue  number of systems developed to simulate reverberation  simple DSPs use multiple feedback delay circuits

8. Impulse response of a room

9.  "whooshing" sound  created by mixing a signal with a slightly delayed copy of itself  considered a particular type of phasing effect

10.  allows the user to magnify or dampen any frequencies  Many equalizers change up to 20 different frequency bands

11.  various effects on pre-recorded sound › Delay › Multiple Echo › All pass Reverberation › A Natural Sounding Reverberation  audio file manipulated in visual dsp++  Output produced on sound card

12.  musicians have been using different techniques  Some of these were found by accident  effects have not changed much in the past few years  from analog signal processing towards digital signal processing  very precise and easily reproduced effects

13.  In movies and theaters  To make voice listened better in different environments  in a recording studio  gives you greater choice of sounds  better control over different devices used  For improving the quality of music

14.  Delay:

15.  Open a file in read mode…  int R=5000;  for(i=0;i<R;i++) y[i] = x[i];  for(j=R;j<xlen;j++) y[j]= x[j]+x[j-R];

16.  Multiple Echo: H(Z) = Z -R / (1 - alpha * ( Z -R ))

17.  int R=5000;  int aa =0.5;  for(i=0;i<R;i++) y[i] = x[i];  for(j=R;j<xlen;j++) y[j]= x[j]+(aa*x[j-R]);

18.  All pass Reverberation:

19.  A Natural Sounding Reverberation:  Schroeder's Reverberator

20. input

21. output

22.  Different sort of effects and filtering techniques  Sound effects are done digitally allowing for a wider variety of manipulation  By the application of DSP, sound quality can be improved