Try apps like Voice Changer Calling, Funcalls, or Call Voice Changer, all of which are available on Android and iOS.
Keep in mind that most of these apps charge per phone call.
Some also let you add sound effects throughout the call. Pick a voice based on what you’re trying to do. If you’re making a prank call, pick a silly voice. If you’re trying to do something serious, pick a more serious voice.
Because you are dialing through the app, typically your number won’t show up.
Also, bear in mind that your voice can be returned to “normal” by the other person with decryption apps.
Make sure to hold the phone up to the computer’s speakers so the person can hear it! Keep in mind, you have to be a fast typist for this to work.
You can find any number of websites that will do text to speech. Just search for “text-to-speech website” in a search engine.
One app you can try is the TK Solution Text-to-Speech app.
Try combining this with other techniques, such as changing the pitch of your voice.
