Simple use case, as to generate a sine wave and adjust its tone is fairly easy and i’m sure with a few minutes of digging thru google, this topic or even youtube you will find the example for it. But once you start dig deeper in the rabbit hole you will require to have a certain amount of understanding it’s obviously the case here as well, just like with anything else in the engine. Audio is not different from any of the other technologies integrated in the engine, so you have to learn the basics first to know which tool you will want to use for your work. It’s not feature complete but rich, and that is good for setting up complex behavior too, tho you may find it less satisfactory for certain use cases. It’s no problem, and i mean not to complaints about the current state, since it is evolving pretty fast and have great improvements by the day you can see this on the github commits.
One thing that i think would be nice to put more time investment is the visual feedback of the setup, and perhaps better modularity to understand what is happening. For instance, i have found NI’s reaktor to be a good example of modular synthesis where i have learned a great ton of basics about how a synth can work, and it allowed me to setup very sophisticated builds for many use cases. Reaktor was never meant to be optimal for real time use (with multiple instances even) but at least you could have a straight idea of what is going on. You can take a look at tools like reaktor that should help. But of course you can go down the path with the basic VST’s as well in free DAW applications you can use them to experiment with the properties of similar functions you can find in the engine as well, since they are ready to use and simple to access.
I would also suggest you to try to setup simple synthesis projects you can test and evaluate the behavior of the engine system, that should give you a huge boost of practical experience too with the ue4 implementation. Start with a sine wave and a fequency modulation, just like the example you have mentioned.