Example of major synthesis quality issue for ISM 13.2 kbps (similars issues at other bitrates as well)

with 1f935c16 and this command line

IVAS_dec MONO 32 bit syn

and the following bitstream,

During music part, everything above 5 kHz is just noise level as shown below

while for speech, even is the difference is less, you can see some strange behavior in high-frequencies

and in Low frequencies, you can observe some problems where there is inter-harmonic noise present in the fixed point version