It depends on your use-case. In many use-cases, it suffices to make a Rapid Voice Clone in Altered Studio by yourself with just 4-8 seconds of audio. For assured production-quality results, it is recommended to contact Altered to train a Custom Voice. To train a Custom Voice, you will need 60-90 minutes of clear and high-quality voice recordings. However, for many Target Voices, good results can be obtained from only 30 minutes of audio. The amount of training data required depends on the proximity of the Target Voice to Altered's dataset. Altered also offers special custom services with less that 30 min of audio, but at a higher cost.