Transform fft phase to write audio

I need to transform the phase (and not amplitude) of a sound and create a new sound file, however ifft() of the transformed array appears complex and cannot be written to audio. Below is my code:

% read the audio file and fourier transform it

[x, Fs] = audioread('Sample.m4a');

y = fft(x,Fs); % Compute DFT of x

Xf_mag = abs(y);

% the phase of each resulting frequency bin was randomly shuffled

Xf_phase = angle(y);

Xf_phase_new=shuffle(Xf_phase);

% The phase-shuffled frequency domain data were then back-transformed to

% the time domain using an inverse Fourier transform

Xf_new = Xf_mag.*exp(1i*Xf_phase_new);

x_new = ifft(Xf_new);

% write a new sound file

filename = 'test.m4a';

audiowrite(filename,x_new,Fs);

I get the following error:

Error using audiowrite (line 170)

Expected input to be real.

Answer 1

[Mathieu NOE]

hello

take the real part after you do the ifft :

x_new = real(ifft(Xf_new));