How can I increase/decrease (frequency/pitch) and phase using fft/ifft tia sal22

[Rick T]

How can I increase/decrease (frequency/pitch) and phase using fft/ifft 
 I think I have the basic code but I’m not sure what to do next 
 
PS: Thanks for the help on the last question everyone I decided not to use the FOR loop and sin/cos values and just use fft/ifft

to see if this will work.

Example I have a signal that repeats 1 time every second and I want to
have it repeat 3 times a second instead.

 %Voiceprint raise lower freq phase conjugate signal
tic
clear all, clc,clf,tic
%% Sound /beep calculation complete
filerawbeepStr='calculations_complete.wav';
filerawbeeppathStr='/home/rat/Documents/octave/raw/';
filevoiceprepathStr='/home/rat/Documents/octave/eq_research/main/
transform/voice/';
filewavpathStr='/home/rat/Documents/octave/eq_research/main/transform/
wav/';
[ybeep, Fsbeep, nbitsbeep] =
wavread(strcat(filerawbeeppathStr,filerawbeepStr));
%addpath(”/home/rat/Documents/octave/eq_research/main/transform/”);
%add path to location of functions

%1a voice print import
[vp_sig_orig, fs_rate, nbitsraw] =
wavread(strcat(filevoiceprepathStr,'voice8000fs.wav'));

%vp_sig_orig=vp_sig_orig’;
vp_sig_len=length(vp_sig_orig);

%2a create frequency domain
ya_fft = fft(vp_sig_orig);
vp_sig_phase_orig = unwrap(angle(ya_fft));

%get Magnitude
ya_fft_mag = abs(ya_fft);

%3a frequency back to time domain
ya_ifft=real(ifft(ya_fft));

%adjust frequency/phase here? How?
vp_sig_new=real(ifft(ya_fft_mag.*exp(i*vp_sig_phase_orig)));

subplot(3,1,1), plot(vp_sig_orig),title('1 original time domain') 

 subplot(3,1,2), plot(ya_ifft),title('2 rebuild time domain') 
 subplot(3,1,3), plot(vp_sig_new),title('3 adjusted time')