For learning about waveform/signal processing, you could start with the Sound of AI channel that teaches signal processing with Python and deep learning for audio with TensorFlow and Librosa. Some hands-on examples (in separate playlists):


16- How to Implement a CNN for Music Genre Classification - YouTube 5


How to Implement Autoencoders in Python and Keras || The Encoder - YouTube 3


How to Extract Spectrograms from Audio with Python - YouTube 1


GitHub repos by the same person:


GitHub - musikalkemist/DeepLearningForAudioWithPython: Code and slides for the "Deep Learning (For Audio) With Python" course on TheSoundOfAI Youtube channel. 1 ;

GitHub - musikalkemist/generating-sound-with-neural-networks: Code and slides for the "Generating Sound with Neural Network" series on The Sound of AI Youtube channel. 2 ;
GitHub - musikalkemist/AudioSignalProcessingForML: Code and slides of my YouTube series called "Audio Signal Proessing for Machine Learning" 1




 Georgschmied:

the loudspeaker has to generate ultrasonic modulated signals,


To learn to generate sounds using the input from your loudspeaker, you might start with the second playlist mentioned above (generating sounds with neural networks).



 Georgschmied:

can make many samples of some random signals and recorded samples


If you’re interested in music source separation, for example, there’s an open sourced model called Spleeter - you can try it on your machine: GitHub - deezer/spleeter: Deezer source separation library including pretrained models. 2 (it was written in TensorFlow). (D3Net is one of the current state-of-the-art models: [2010.01733] D3Net: Densely connected multidilated DenseNet for music source separation 3 .)
More material:

DeepMind: WaveNet: A generative model for raw audio | DeepMind 2 (paper: WaveNet: A Generative Model for Raw Audio | DeepMind)
DeepMind: The challenge of realistic music generation: modelling raw audio at scale | DeepMind 1 (Talk: Sander Dieleman: Generating music in the raw audio domain - YouTube)
Google Brain Magenta: GANSynth: Adversarial Neural Audio Synthesis | OpenReview 1 (magenta/magenta/models/gansynth at master · magenta/magenta · GitHub)
Magenta: Music Transformer: Generating Music with Long-Term Structure 2

Magenta’s repo: GitHub - magenta/magenta: Magenta: Music and Art Generation with Machine Intelligence 2 (and magenta/magenta/models at master · magenta/magenta · GitHub)
Generating music in the waveform domain – Sander Dieleman 1
arXiv: [1911.13254] Music Source Separation in the Waveform Domain 1