audiostream | Audio API for streaming raw data to speakers | Audio Utils library

Working solution:
Removing the audioStream.play() from where the JsSIP call is answered solves the issue.
I don't know the exact reason why this solves the issue (it might even be a workaround) but after much trial and error this way allows the audio to be available to ToneJS for effecting.

Any other solutions are welcome.

You have done too many API actions in YouTube. If you reach 10.000 points per day you are limited. Read about it here: https://developers.google.com/youtube/v3/getting-started#quota

And you can read about similar things in another StackOverflow Question.

The #1 suggestion is by Mark Rotteveel. The AudioInputStream class needs closing. This is often a surprise for people, because Java is well known for managing garbage collection. But for AudioInputStream there are resources that need to be released. The API doesn't do an adequate job of pointing this out, imho, but the need for handling can be inferred from the description for the AudioInputStream.close() method:

Closes this audio input stream and releases any system resources associated with the stream.

The #2 suggestion is from both Andrew Thompson and Hendrik may be more a helpful hint than a direct solution, but it is still a very good idea, and it seems plausible to me that the inefficiency of all the additional, unneeded infrastructure (ClassLoader, InputStream, BufferedInputStream) might be contributing to the issue. But I really don't have a good enough understanding of the underlying code to know how pertinent that is.

However, I think you can do even better. Don't use Clip. You current use of Clip goes against the concept of its design. Clips are meant for short duration sounds that are to be held in memory and played multiple times, not files that are repeatedly reloaded before each playback. The proper class for this sort of use (load and play) is the SourceDataLine.

An example of playback using a SourceDataLine can be found in the javasound wiki. This example also illustrates the use of URL for obtaining the necessary AudioInputStream. I will quote it here verbatim.

Thank you for your comprehensive answer.

I just switched to ALSA from Pulseaudio. It works fine.

There are some defaults not listed in the documentation. Try adding the following to your config and see whether it works

Since you don't include more of the API for a specific call I can't directly answer your implementation question, but I will address the portion of the question that asks about the types.

In C (and C++), arrays are stored in contiguous native memory. If you know the type (float in this case) you can simply offset from the pointer to get the appropriate element, e.g., foo[0] is at the pointer location to the array, foo[1] would be at that pointer location plus an offset equal to the type byte size (4 bytes for a float) and so on.

The Pointer and PointerByReference are JNA types. PointerByReference is a pointer that points to a Pointer; you can call the getValue() function on the PointerByReference() to retrieve this pointer.

Based on the way I read this API, that Pointer is actually the beginning of the float array, so you'd just use that Pointer and retrieve the array from its location.

So this is likely what you need to do:

You're not doing anything wrong, but it only outputs JSON if you're looking for speech marks. Try switching to an audio output format like MP3 as shown below.

After thinking about this some more, I realised that I wasn't even sure if my decoder was correct. And another thorough inspection of the transcoding example revealed a small difference in behaviour.

Effectively, I was doing this:

The implementation is correct.

The documentation confirm that you have to update the token to allow the metadata to be refreshed. I tested and It work properly.

Based on your comments, it seems that the issue persist on your Fire HD 8 Tablet with the Fire OS version 7.3.2.1.

It's always a good practice to try on different devices to validate the root cause.

I recommend you to contact the developer directly on the amazon developer forum. They should be able to push a fix for the device and fireOS version.