I'm afraid you're misunderstanding the complexity of the hearing organ. A sine sweep is an even more crude measurement than an audiometric test, because it has some issues. From the top of my head I name a few;
- A sine sweep is used on a certain volume (loudness), so it only tests your hearing for the ranges of the sine sweep on this certain loudness level. Your cochlea contains hair cells which detect sounds at different frequencies but ALSO different volume levels. It might for instance be, that you can hear 15khz perfectly at a louder volume level, but not at a lower volume (while you could have heard it BEFORE your acoustic trauma at this lower volume level). This is because your cochlea has OUTER hair cells, which detect sounds at LOWER volume levels, and INNER hair cells, which detect sounds at LOUDER volume levels. Damage to the outer hair cells is for example not tested when you use the sine sweep test at a louder volume level. Outer hair cells also appear to be the first hair cells to be damaged upon trauma, meaning you will most probably lose your ability to register high-frequency noises at low volume levels first (the outer hair cells for high frequencies are located near the entrance or base of the cochlea and thus take the biggest hit upon incoming soundwaves).
- A sine sweep does not test your ability to hear sounds in background noise. This is what "hidden hearing loss", also known as "cochlear synaptopathy" is. It is your ability to comprehend speech in background noise.
Hearing is way more complicated than such a simple test can show you. It is one of the most complex organs in our body and, unfortunately, one of the least understood.