People and cultures have varying rates of speech delivery and comprehension. One thing that we learned early in the IVR era was that when it comes to receiving instructions and information via audio, often normal feels fast and slow feels just right
Amazon has announced that they've joined the other major providers and enabled Alexa to give verbal output at seven different speeds. While we'd argue that, despite the quote, the need is much more about preference and context than physical conditions, it's welcome all the same.
Some of our hard of hearing and older customers ... would like her to slow down so they can better understand her responses. On the other hand, some of our customers who are blind or low vision are used to consuming audio content and want to be able to listen more quickly.