Interesting. My high frequency cuts out at around 14 kHz.Yep and even if you can't hear it can cause damage, here is a warning on another tone generator site:
"Warning!: People can’t hear sounds < 20 Hz and > 10,000 Hz very well. If you turn up the volume on your device to compensate, you could expose yourself to harmful sound levels and your speakers to harmful currents. To be safe, note the volume level that allows you to listen to a 1,000 Hz tone without discomfort and do not stray too far above this level, even if you can’t hear much – especially in the high range, where your hearing is the most fragile."
While I could still hear all the way down to 12 Hz, I didn't want to hear that for very long, it started to give me a headache and a nauseated feeling.
Early 50s/empty stomach.
This is all assuming the tone generator's Hz number is accurate and my headphones produce sound accurately.
If nothing else, with the lack of perimeter seal on your battery, your car technically has a "hole" leading to the cabin, and therefore a safety defect (if it were an ICE vehicle) as it would allow exhaust leaks into the cabin.