To disguise your voice there are some very easy to use apps available on the Google Play Store and the App Store. Unfortunately, they're not free
Apps to change the tone of your voice, add any special effects to avoid being recognized and a background sound, during a phone call, are certainly not lacking for iOS and Android, but not all of them are up to the task.
We've selected five that work for both Android and iOS. They're apps that look like they're free, but actually only offer a few minutes of trial time or the ability to record a demo to assess the quality of voice changes and special effects. Once the free minutes are over, in most cases, you'll have to buy extra time in-app. And the cost per minute is not always specified. They are, therefore, a nice tool to make some goliardic jokes to friends and relatives, but they are certainly not professional applications as we often see in American TV shows. However, they are worth a try if you want to have some fun with something original.
Call Voice Changer
Here is an application that can change the tone of your voice during a call that offers you a good number of audio effects. Before you buy it, you can try it out in demo mode which allows you to hear if the voice change suits you and find out how other people will hear you. The first two minutes are free and must be "spent" within the first two weeks. Prices then range from £1.09 for 3 minutes to £43.99 for 170 minutes. Call Voice Changer is available for iOS and Android.
Funny Call / Minion Prank Call
An app and two names? Well yes: it's called Funny Call in iOS and Minion Prank Call in Android. But it's the same app made by the same developer. The user interface is a bit chaotic, but once you get the hang of it, it's pretty simple to use. It doesn't allow you to make a test call to check the results of the voice change, but it does allow you to record yourself to test the audio effects. Half of the effects to disguise the way you speak are free, but if you want the entire collection, you have to pay. The app, unfortunately, displays some rather annoying advertisements that take up the entire screen and force you to play the game in order to close them. They don't show up, thankfully, too often. The first 30 seconds are free, then, like Call Voice Changer, and other similar tools, it gives you various in-app purchases to choose from. Funny Call / Minion Prank Call is available for iOS and Android.
FunCall
FunCall comes with a very easy to use interface and also has a feature to make a test call so you can listen to the voice change. It doesn't offer the same number of effects Funny Call has, but it provides you with five basic voice effects: Helium, Woman, Man, Scary and Normal. You can also add additional sound effects during the call such as gunshots, a barking dog, a werewolf and more. Calls are made using Wi-Fi, not the cellular network. You can purchase additional effects via in-app purchases that range from €0.99 to €19.99 depending on your choice. FunCall is only available for Android.
Voice Changer Calling
A very easy to use app for changing your voice during a phone call: when you open Voice Changer Calling you will immediately see the keypad for dialing the number and voice effects located in the upper right corner. The application uses Wi-Fi to make calls and you can purchase credit that costs $5, $10 and $20 (about $4.5, $9 and €18 at current exchange rates). There are only five voice effects available: deep, scary, normal, funny and "squirrel". Voice Changer Calling is only available for Android.
Call Voice Changer Allogag
The interface of Call Voice Changer Allogag is very intuitive and comes with three tabs: Voice Changer, Background and Effects. Call Voice Changer Allogag does not allow you to make a test call, but you can record your voice to try out the tone change and effects. The downside is that it only has three settings for your voice: lowest, normal and highest tone. It offers one minute for free, then you need to purchase extra minutes to continue using it. In-app purchases: range from €1.09 to €79.29. Call Voice Changer Allogag is available for Android only.