Source: https://jmrplens.github.io/phonometry/reference/api/psychoacoustics/roughness-ecma/ Psychoacoustic roughness per ECMA-418-2:2025 (4th ed., Sottek Hearing Model). Clean-room implementation of the roughness signal chain of ECMA-418-2:2025 (Clause 7). The shared auditory front-end (Clause 5: outer/middle-ear filter, 53-band gammatone-like filter bank, half-wave rectification, compressive nonlinearity to the specific basis loudness `N'_basis(l, z)` of Formula 25) is reused from [`.loudness_ecma`](/phonometry/reference/api/psychoacoustics/loudness-ecma/#loudness_ecma); this module adds the roughness-specific chain: * roughness-specific zero-padding (Clause 5.1.2.2) and segmentation (Clause 5.1.5.2) with the fixed block/hop `s_b = 16384` / `s_h = 4096` (Clause 7.1.1); * the Hilbert envelope of each critical-band block and a factor-32 downsampling to 1500 Hz (Clause 7.1.2, Formula 65); * the scaled envelope power spectrum `Phi_E,l,z(k)` (Clause 7.1.3, Formulae 66-67); * the two-step noise reduction of the envelope spectra (Clause 7.1.4, Formulae 68-71); * the four-stage spectral weighting (Clause 7.1.5, Formulae 72-96): peak picking with a quadratic-fit modulation-rate refinement and a bias correction, the high-modulation-rate weighting, the fundamental modulation-rate estimation, and the low-modulation-rate weighting; * the interpolation to 50 Hz, the distribution-dependent nonlinear transform with the calibration constant `c_R`, and the asymmetric time smoothing (Clause 7.1.7, Formulae 103-110); and * the average specific roughness `R'(z)` (Clause 7.1.8), the time-dependent roughness `R(l50)` (Clause 7.1.9, Formula 111) and the representative 90th-percentile single value `R` (Clause 7.1.10). The optional entropy weighting of Clause 7.1.6 requires an external rotational speed signal and is not implemented (see `notes-ecma418-2-roughness.md`). The API is monaural: the quadratic-mean binaural combination of Formula (112) (Clause 7.1.11) is not implemented -- analyse each channel separately. The calibration constant `c_R` of Formula (104) is the standard's tabulated value (not reverse-fit), and the chain reproduces the Clause 7 reference point exactly: a 1 kHz carrier 100 %-amplitude-modulated at 70 Hz with an overall sound pressure level of 60 dB SPL computes to 0.9999 asper against the defined 1 asper. Note the level convention: Clause 7 states the *sound pressure level of the signal* (its overall RMS level), not the level of the unmodulated carrier -- a fully modulated signal whose carrier alone sits at 60 dB is +1.76 dB hot overall and reads ~4 % high. > Auto-generated from the source docstrings by `scripts/generate_api_docs.py` (`make api-docs`). Do not edit by hand. ## EcmaRoughness ```python EcmaRoughness( roughness: float, specific_roughness: np.ndarray, bark: np.ndarray, centre_frequencies: np.ndarray, time: np.ndarray, roughness_vs_time: np.ndarray, specific_roughness_vs_time: np.ndarray, field: str, ) ``` Result of an ECMA-418-2:2025 (Sottek) roughness calculation. `roughness` is the single representative roughness R in asper (the 90th percentile of R(l50), Clause 7.1.10). `specific_roughness` is the average specific roughness R'(z) in asper/Bark_HMS over the 53 auditory bands (Clause 7.1.8), with `bark` the critical-band-rate scale z (0.5..26.5 Bark_HMS) and `centre_frequencies` the band centre frequencies F(z). `time` and `roughness_vs_time` hold the time-dependent roughness R(l50) at 50 Hz (Formula 111); `specific_roughness_vs_time` is the time-dependent specific roughness R'(l50, z) (Formula 109) of shape `(n_times, 53)`. `field` records the assumed sound field. ### EcmaRoughness.plot() ```python EcmaRoughness.plot( ax: Axes | None = None, *, language: str = 'en', **kwargs: Any, ) -> Axes | np.ndarray ``` Plot the roughness result (see `._plotting`). Draws the time-dependent roughness R(l50) and a specific-roughness heatmap. Requires matplotlib (`pip install phonometry[plot]`). ## roughness_ecma ```python roughness_ecma( signal_in: np.ndarray, fs: float, field: Literal['free', 'diffuse'] = 'free', ) -> EcmaRoughness ``` Psychoacoustic roughness per ECMA-418-2:2025 (Sottek Hearing Model). **Parameters** | Name | Description | | :--- | :--- | | `signal_in` | Calibrated sound pressure signal in pascals. | | `fs` | Sampling rate in Hz. Signals not at 48 kHz are resampled (Clause 5.1.1). | | `field` | `"free"` (default) or `"diffuse"` sound field, selecting the outer/middle-ear filter of Clause 5.1.3. | **Returns:** An [`EcmaRoughness`](/phonometry/reference/api/psychoacoustics/roughness-ecma/#ecmaroughness) with the single value R (Clause 7.1.10), the average specific roughness R'(z) (Clause 7.1.8) and the time-dependent roughness R(l50) (Formula 111). A 1 kHz carrier 100 %-amplitude-modulated at 70 Hz with an overall level of 60 dB SPL yields 1 asper (Clause 7 calibration; reproduced to 0.9999 asper with the tabulated c_R of Formula (104)).