Hello Sergio D'Orazio,
You may list the available packages on the BSP by running:
$ bitbake -s
You may search for the pulseaudio available packages using grep from this output:
$ bitbake -s | grep pulseaudio
You may add any package using the following addition to your conf/local.conf file:
IMAGE_INSTALL_append = “ package”
In this case:
IMAGE_INSTALL_append = “ pulseaudio”
I hope this helps!
Regards,