You can continue to call out, use the rattle toys or anything squeaky sound close by and see if baby turn left or right. Then upon the next check up for baby,do raise your concern to the doctor and they will do assessment. It may be too early. But most baby will turn to noise/voice when they hear. Some baby may take awhile to react to noise/voice. Therefore, highly advice to have it raised should it be a concern and worrying for you.
Some babies are late bloomers according to the GP at polyclinic. So I think it’s quite normal.