<speak>
<audio src = "https://s3.amazonaws.com/morsecodesounds/Is.mp3" />
<audio src = "https://s3.amazonaws.com/morsecodesounds/Ie.mp3" />
<audio src = "https://s3.amazonaws.com/morsecodesounds/Il.mp3" />
<audio src = "https://s3.amazonaws.com/morsecodesounds/Ie.mp3" />
<audio src = "https://s3.amazonaws.com/morsecodesounds/Ic.mp3" />
<audio src = "https://s3.amazonaws.com/morsecodesounds/It.mp3" />
</speak>
This is what i tested on the alexa developer console did not play it.
Just to wrap this up nicely for anyone looking for the answer: https://developer.amazon.com/docs/custom-skills/handle-requests-sent-by-alexa.html
"When Alexa renders this response, it would sound like this:
Alexa: Welcome to Car-Fu. (the specified amzn_sfx_car_accelerate_01.mp3 audio file plays) Alexa: You can order a ride, or request a fare estimate. Which will it be?"
The audio files you include within your service's response must be very short to ensure a good user experience. You can include up to five audio files in a single response. The combined total time for all audio files in a single response cannot be more than 240 seconds. For specific requirements and limitations on the audio files, see Speech Synthesis Markup Language (SSML) Reference.
For more about using SSML in your responses and other supported tags, see Speech Synthesis Markup Language (SSML) Reference"