The following article provides steps for changing the way Siri sounds.
Can I change how Siri sounds?
New female and male voices will be available initially in U.S. English, French, and German. You can change the gender by going to Settings > General > Siri > Voice Gender. Your iOS device initially uses a compact voice for Siri. iOS will automatically download and install a more natural-sounding voice when you first connect to power and a Wi-Fi network.