To use Polly voices in an Alexa skill, have your Lambda function call Polly and return the audio through SSML in the skill response. You do not need the MP3 download and re-upload conversion steps from old tutorials; Polly output can be referenced directly. Keep the Polly call and the Alexa response in the same region to avoid cross-region latency on every turn.

Context: Stack Overflow #43863489 (accepted answer, 6 votes): asked whether Amazon Polly can be used inside an Alexa skill, for example to deliver a two-language response in a translation context, and how to call it from a Lambda function. The accepted answer walks through a Lambda-backed skill that calls Polly, and notes Polly now works with Alexa without the old MP3 conversion pipeline that early tutorials required.