How to export a reverse sound?

I use -frequency to implement a reverse effect.But there is no sound when I export to a .wav file.I guess the minus frequency is a playback feature that supported by FMOD.The audio file can not recognize a minus frequency audio.
I thought a idea that reverse write the audio file, but I want some easy steps.Does anybody have some ideas?

FMOD Studio does not support using negative frequency to play audio files backwards.

It sounds like you’re attempting to produce audio files that can be used outside of a gaming context. I recommend you use a DAW such as Protools or Live to produce this kind of content; You will get better results when using a tool that’s designed for what you’re trying to do.