digital-audio

Digital audio is a system for representing and processing audio as discrete digital signals. The removal test: remove signals and digital audio ceases to operate — it has nothing to process. This is an object-level dependency: digital audio is fundamentally about signal manipulation, not a meta-level conceptual dependence.

Pitch-shift is built and maintained for the sake of digital-audio applications — music production, voice conversion, and sound design all depend on pitch manipulation. Remove pitch-shift and these audio workflows lose a core capability. The servant points at the master: pitch-shift serves digital-audio.

Phase-vocoder is a spectral manipulation procedure built for the sake of digital-audio applications — time-stretching, pitch-shifting, and cross-synthesis all rely on phase-vocoder resynthesis. Remove phase-vocoder and these audio processing workflows lose their primary mechanism. The note describes the designed purpose, not incidental benefit.

audio-compression is built and maintained for the sake of digital-audio — it reduces the storage and bandwidth requirements of digital audio without destroying fidelity. Its design purpose is to make digital audio practical for storage and transmission. Servant (audio-compression) points at master (digital-audio).

Spectral flangers are built for digital audio workflows — the spectral analysis and phase-vocoding techniques they use operate specifically in the digital domain. Remove digital-audio and spectral flangers have no practical application context.

CPP extracts periodicity features from speech signals, and these features are consumed by digital-audio applications — voice conversion, speech synthesis, and pitch manipulation all depend on CPP extraction. Remove CPP and these audio processing pipelines lose a core feature, though they still operate with alternative features.

Formant tracking as practiced today requires digital audio data as input. Remove digital audio and formant tracking stops operating — it has no data to analyze. The removal test passes.

Audio-plugin is a specific kind of digital-audio software: it runs inside a host application to process or generate audio digitally. A speaker would call it 'a digital audio application/plugin.' Nearest kind among existing entries is digital-audio.

Post-echo is a specific artifact that occurs within digital audio processing. Digital audio is the broader domain. Direction correct (digital-audio older, post-echo at 0.86). Post-echo IS a type of digital audio artifact.

Audio dithering is built and maintained for the sake of improving perceived quality and preventing artifacts in digital audio reproduction.

Audio-watermarking embeds data into digital audio waveforms; remove digital audio as the medium and the technique has no operation to improve. Operational dependency.