Sound Channel Purity - Windows 10 Settings

Hello,

my problem is that when using following script:

fs = 48000;
sig_freq = 1000;
t = 0:(1/fs):5;
sig = sin(sig_freq*2*pi*t);
ears_active = [0;1];
binaural = ears_active*sig;
sound(binaural, fs);

I can hear a sound little bit from the left channel of my earphones. (Despite that the script is programmed to play a single (right) channel tone).

To fix this I probably need to set something in the Windows Sound settings correctly.

But every sound setting which I could reach I set to 'None', except 'Windows Default', and the problem still persists.

I also tried MaxxAudio wizard, but it is set to the 'OFF' option.

Thanks in advance

PL.