Edit exisint Audio file

I have a audio track what is unfortantly overrated and like this i cannot use it for an Fone System. The Power is to high and it's overregulating. Need someone who can adapt the settings to have a clear sound for a fone System.
End Format has to be WAV (PCM, 8 kHz, 16 Bit, Mono, Max. Size: 100 MB)

Need it as clear as possible and without of over regulating