Use audio recording during a VoIP phone call

Hey!

So I was wondering if there is a VoIP softphone/Software that allows you to use an audio recording (wav, MP3 etc) during a phone call?

This would obv replace me speaking into the mic every phone call I make. The reason I ask is that this would be beneficial for my dissertation project.

I have searched online and asked my supervisor for my dissertation project and have been unsuccessful to date to see such a softphone or software that enables it.

Would be very appreciated if anyone can recommend a softphone or software capable of this.

Thanks.