Source: https://jmrplens.github.io/phonometry/reference/api/metrology/calibration/ Calibration utilities for mapping digital signals to physical SPL levels. > Auto-generated from the source docstrings by `scripts/generate_api_docs.py` (`make api-docs`). Do not edit by hand. ## CalibrationWarning The calibration reference recording looks unreliable. ## sensitivity ```python sensitivity( ref_signal: list[float] | np.ndarray, target_spl: float = 94.0, ref_pressure: float = 2e-05, fs: int | None = None, validate: bool = True, max_fluctuation_db: float | None = None, frequency: float = 1000.0, narrowband: bool = False, ) -> float ``` Calculate the calibration factor (multiplier) to convert digital units to Pascals based on a reference recording (e.g., 1kHz @ 94dB). When `fs` is provided (and `validate` is True), the recording's stability is checked the way IEC 60942:2017 specifies for the calibrator itself (5.3.3): levels are measured with time-weighting F and the *short-term level fluctuation* (the absolute difference between each of the maximum and minimum levels and the mean level) must not exceed the Table 2 acceptance limit for the calibrator class (class 1: 0.07 dB at and above 160 Hz, relaxed to 0.10 dB above 63 Hz and below 160 Hz, and to 0.20 dB for the 31.5-63 Hz rows where the F time-weighting itself ripples; below Table 2's 31.5 Hz span the strict 0.07 dB applies). A larger fluctuation usually means a badly coupled microphone or handling noise in the recording, which would silently corrupt every calibrated level; a [`CalibrationWarning`](/phonometry/reference/api/metrology/calibration/#calibrationwarning) is emitted. :::note IEC 60942 certifies calibrators over 60 s of operation sampled at least 30 times; this check applies the same criterion to whatever settled portion of the recording is available (>= 1 s after the 1 s integrator attack). ::: **Parameters** | Name | Description | | :--- | :--- | | `ref_signal` | Recording of the calibration tone. | | `target_spl` | The known SPL level of the calibrator (default 94 dB). | | `ref_pressure` | Reference pressure (default 20 microPascals). | | `fs` | Sample rate of the recording in Hz. Required for the stability validation; without it the check is skipped. | | `validate` | If True (default) and `fs` is given, warn when the recording's short-term level fluctuation exceeds the limit. | | `max_fluctuation_db` | Explicit fluctuation limit in dB. Default (None) resolves the IEC 60942:2017 Table 2 class 1 limit for `frequency`. | | `frequency` | Nominal frequency of the calibration tone in Hz (default 1000.0), used to select the Table 2 row. | | `narrowband` | If True (requires `fs`), estimate the tone level with a coherent single-frequency (Goertzel) detector locked to the tone near `frequency` instead of the full-band RMS. This rejects broadband hum/noise in the reference take, which otherwise inflates the RMS and shrinks the factor by $-10 \log_{10}(1 + 1/\mathrm{SNR})$ (about -0.44 dB at 20 dB SNR), silently biasing every subsequent level. The default (False) keeps the exact legacy broadband-RMS behaviour; enable it for noisy coupler recordings. | **Returns:** Calibration factor (sensitivity multiplier).