How can we send media response without speech?

I have tried to send response without addSimpleResponse:

app.ask(app.buildRichResponse()
// removed speech response
//      .addSimpleResponse('')
      .addMediaResponse(app.buildMediaResponse()
        .addMediaObjects([app.buildMediaObject(
          strings.title,
          options.audioURL
        )
          .setDescription(description)
          .setImage(
            options.imageURL || config.media.DEFAULT_SONG_IMAGE,
            app.Media.ImageType.LARGE
          )
        ])
      )
      .addSuggestions(options.suggestions)
      .addSuggestionLink(
        mustache.render(strings.suggestionLink, options),
        mustache.render(config.endpoints.ALBUM_DETAIL, options)
      )
    );

and with empty addSimpleResponse

app.ask(app.buildRichResponse()
// muted speech response
      .addSimpleResponse('')
      .addMediaResponse(app.buildMediaResponse()
        .addMediaObjects([app.buildMediaObject(
          mustache.render(strings.title, options),
          options.audioURL
        )
          .setDescription(description)
          .setImage(
            options.imageURL || config.media.DEFAULT_SONG_IMAGE,
            app.Media.ImageType.LARGE
          )
        ])
      )
      .addSuggestions(options.suggestions)
      .addSuggestionLink(
        mustache.render(strings.suggestionLink, options),
        mustache.render(config.endpoints.ALBUM_DETAIL, options)
      )
    );

But all the time gets fail:

{
  "message": "Failed to parse Dialogflow response into AppResponse, exception thrown with message: Empty speech response",
  "apiResponse": {
    "id": "786399ec-fe7f-432d-aa26-4628802d0b05",
    "timestamp": "2018-03-14T13:28:46.777Z",
    "lang": "en-us",
    "result": {},
    "status": {
      "code": 206,
      "errorType": "partial_content",
      "errorDetails": "Webhook call failed. Error: 400 Bad Request"
    },
    "sessionId": "1521034108233"
  }
}

In the same time it works with speech response fine. _I’ve grab working code right from our sources https://github.com/internetarchive/internet-archive-google-action/blob/master/functions/src/dialog/audio.js#L20_

How can I send media response without speech?

[igilham]

For a clip of silence, you might be violating the general policies where it says Playing a silent sound file without a clear purpose may get your app rejected from the directory in the review process since it’s not the best user experience.

Maybe a short (not too loud) sound effect can be better to let the user know the next media is playing. But you should test it out with users to see what they are fine with.

What if the clear purpose is to work around a bad UX design decision by the Assistant platform? Playing SSML in between audio files in a playlist is terrible UX.

Assistant is also a bit buggy. I starts playing the MediaResponse silently, speaks the SSML over the top, then continues playing the audio file from part way through, having skipped the first few seconds (up to 120s).

[nealrs]

@igilham re: that SSML issue, I’ve definitely had this problem and filed a bug with the AOG team directly (1-2 months ago). they claim it’s been fixed - but if you’re still seeing it, you may want to email them with an example recording/video.

and i totally agree re: required SSML between audio clips being a bad UX.