You can record any audio (for Auto-Attendants, User/Department Name, Hold Messages or Voicemail prompts, etc.) using Text-to-Speech.  Type in the text and select the voice actor.

Some of the audio prompts have the Text-to-Speech option under the ‘Change’ menu; if you don’t see it there, select ‘Pick from Media Library’, then ‘Add New Audio’/’Text to Speech’. Here you can type in a name and the text you want, and select a voice actor. The audio will be added to your Media Library as well as the audio prompt you are changing. Try experimenting with the various voice actors to find the one that best suits your needs.

In order to make the final audio sound more realistic, you can add pauses between phrases, sentences, or paragraphs using certain codes. Each code starts with <break and ends with />. You can specify the strength (i.e., the length) of the break, or specify a time in seconds or milliseconds to be very specific. As an example:

Thank you for calling Bob’s Text to Speech Emporium. If you are a current customer, please press 1 now. <break time='2s' /> To reach our Sales department, press 2; to talk to one of our Support staff press 3.

In this example, there will be a 2 second pause between the 2^nd and 3^rd sentence.

The list of pause codes is as follows:

• "This is not a pause." 
• "This is a <break strength='x-weak' /> phrase break." 
• "This is a <break strength='weak' /> phrase break." 
• "This is a <break strength='medium' /> sentence break." 
• "This is a <break strength='strong' /> paragraph break." 
• "This is a <break strength='x-strong' /> paragraph break." 
• "This is a <break time='3s' /> three second pause." 
• "This is a <break time='4500ms' /> 4.5 second pause." 
• "This is a <break /> sentence break."