speech-processing

Speech processing (analysis, synthesis, enhancement) is built and maintained for the sake of improving how well speech can be understood — speech intelligibility is its designed purpose. Servant (speech-processing) points at master (speech-intelligibility) per Law 8d.

A formant vocoder synthesizes speech by modeling vocal tract resonances (formants) and serves speech processing by providing a parametric approach to speech analysis and synthesis. It is a tool used within speech processing pipelines for vocoder-based processing and analysis.

Pitch-synchronous processing is a specific kind of speech-processing method. It aligns analysis and synthesis with pitch periods, a task intrinsic to speech/audio processing. Nearest kind is speech-processing.

Serves test (Law 8d, for whose sake): the vocoder was built for whose sake? Human speech. Homer and Flono's 1928 vocoder analyzed speech into formant-band envelopes and resynthesized it for transmission — the parameters it preserves (band envelope amplitudes) are precisely the speech parameters, and its original and continuing primary application is speech analysis and transmission. It is not an ambient discipline (contrast: X DEPENDS_ON mathematics strikes) — speech-processing is the specific purpose-built discipline the device was constructed for. Direction: vocoder (servant) -> speech-processing (master). Pinned sense: speech-processing as the discipline the vocoder was built to serve, not as a category it belongs to (hence SERVES, not INSTANCE_OF).

The phase-locked vocoder is a speech synthesis technique specifically designed for speech processing — its purpose is to process and synthesize speech signals with phase coherence. Servant (phase-locked-vocoder) points at master (speech-processing).

Speech-enhancement is a specific kind of speech-processing task. Nearest kind is speech-processing.

Cepstral analysis is a specific speech-processing technique that represents speech signals using cepstral coefficients (log power spectrum via DFT). It is a concrete method within the broader domain of speech processing.

The concept of formants was developed through spectral analysis of speech signals. Speech processing existed first and fed into the formant concept.

Cepstral peak prominence is designed and maintained for the sake of speech-processing: it quantifies vocal clarity by measuring the relative prominence of the cepstral peak corresponding to fundamental frequency. Without speech-processing applications (voice quality assessment, prosody analysis, pathology detection), cepstral-peak-prominence would have no reason to be computed or maintained — its entire purpose is to serve speech analysis systems.