In your web browser, visit https://azure.microsoft.com/
Click the Free account link at the top, then click the Start free button. Then, you can use your e-mail to sign up, or sign into an existing Microsoft account.
Microsoft may require additional steps such as e-mail verification before you can log in to your account.
Once you have completed the verification process and are logged in, go to the Speech Services section under AI + Machine Learning to create a Speech Service resource.
You will likely need to create a new Resource group. For the Instance Details, create a unique name. You can just choose a name you like and add some random numbers to the end. For Pricing Tier, there's only one choice since it's a free account.
Click Review and Create at the bottom.
Under overview, click the copy button on Key 1 to copy it to your clipboard. You can click the Show Keys button as well if you want to view it.
Add this secret key and the region to /etc/environment
. From the command line, you can open it in your favorite editor and add:
SPEECH_KEY="4f1d...02a9"
SPEECH_REGION="eastus"
You will need to reboot before it will be loaded into your environment variables.
Using a Different Voice
Azure Speech Services includes a number of different voices. In their Voice Gallery, you can listen to the different voices and get the Voice Name to change in your code.