API Reference

The complete public API, one page per module. Import the domain subpackage and call through it:

Auto-generated from the source docstrings by scripts/generate_api_docs.py (make api-docs). Do not edit by hand.

from phonometry import filters, underwater

spl, freq = filters.octave_filter(x, fs)
snr = underwater.passive_sonar_equation(185.0, 60.0, 50.0)

Every documented name can also be imported directly from the top-level package (from phonometry import leq).

Filters and frequencies

Module	Summary
`phonometry`	Package-level names defined in `phonometry/__init__.py` itself.
`filters.core`	Core processing logic and FilterBank class for phonometry.
`filters.weighting`	Weighting filters (A, B, C, D, G, AU, Z), time weighting utilities and the Linkwitz-Riley crossover.
`filters.equalizer`	Parametric equalizer biquads per the RBJ Audio EQ Cookbook.
`filters.frequencies`	Frequency calculation logic according to ANSI/IEC standards.
`filters.compliance`	IEC 61260-1:2014 band-filter class verification.
`filters.weighting_compliance`	IEC 61672-1:2013 frequency-weighting class verification.

Signal analysis

Module	Summary
`signals.levels`	Integrated and statistical sound levels (Leq, LAeq, LN percentiles).
`signals.spectra`	Calibrated spectral-density estimation with statistical error analysis.
`signals.multitaper`	Thomson multitaper spectral estimation (Percival & Walden 1993, Ch.
`signals.windows`	Figures of merit of a spectral-analysis taper (Harris 1978).
`signals.miso`	Multiple and partial coherence of a multiple-input/single-output system.
`signals.time_frequency`	Calibrated time-frequency analysis: STFT spectrogram and zoom FFT.
`signals.test_signals`	Test signals and sample-rate utilities.
`signals.phase`	Phase utilities: minimum phase, group delay and excess phase.
`signals.cepstrum`	Cepstral analysis: real/power/complex cepstrum, liftering and echo detection.
`signals.synchronous_average`	Time synchronous averaging (TSA) of a periodic waveform in noise.
`signals.inversion`	Regularized spectral inversion with frequency-dependent regularization.
`signals.correlation`	Correlation analysis and time-delay estimation.
`signals.envelope`	Envelope and instantaneous phase via the Hilbert transform.

Calibration and uncertainty

Module	Summary
`metrology.calibration`	Calibration utilities for mapping digital signals to physical SPL levels.
`metrology.uncertainty`	Measurement uncertainty by the GUM and its Monte Carlo supplement.
`metrology.data_qualification`	Random-data qualification: stationarity tests and Rice crossing statistics.

Psychoacoustics

Module	Summary
`psychoacoustics.loudness.zwicker`	Zwicker loudness for stationary and time-varying sounds per ISO 532-1:2017.
`psychoacoustics.loudness.moore_glasberg`	Stationary loudness per ISO 532-2:2017 (Moore-Glasberg method).
`psychoacoustics.loudness.moore_glasberg_time`	Time-varying loudness per ISO 532-3:2023 (Moore-Glasberg-Schlittenlacher).
`psychoacoustics.loudness.ecma`	Psychoacoustic loudness per ECMA-418-2:2025 (4th ed., Sottek Hearing Model).
`psychoacoustics.loudness.contours`	Normal equal-loudness-level contours per ISO 226:2023.
`psychoacoustics.quality.sharpness`	Sharpness per DIN 45692:2009-08.
`psychoacoustics.quality.roughness_ecma`	Psychoacoustic roughness per ECMA-418-2:2025 (4th ed., Sottek Hearing Model).
`psychoacoustics.quality.tonality`	Prominent discrete tone assessment per ECMA-418-1:2024 (3rd edition).
`psychoacoustics.quality.tonality_ecma`	Psychoacoustic tonality per ECMA-418-2:2025 (4th ed., Sottek Hearing Model).
`psychoacoustics.quality.tone_audibility`	Objective audibility of tones in noise — engineering method (ISO/PAS 20065:2016).
`psychoacoustics.quality.fluctuation_strength`	Fluctuation strength after Fastl & Zwicker / Osses et al.
`psychoacoustics.quality.fluctuation_strength_ecma`	Psychoacoustic fluctuation strength per ECMA-418-2:2025 (4th ed., Clause 9).
`psychoacoustics.quality.annoyance`	Psychoacoustic annoyance (PA) after Fastl & Zwicker.
`psychoacoustics.erb_scale`	The ERB_N scale: auditory-filter bandwidth and the Cam frequency scale.

Speech

Module	Summary
`speech.sti`	Speech Transmission Index (STI) per IEC 60268-16:2020 (Edition 5).
`speech.sii`	Speech Intelligibility Index (SII) per ANSI S3.5-1997 (R2017).
`speech.objective_intelligibility`	Short-Time Objective Intelligibility (STOI and ESTOI).

Hearing and exposure

Module	Summary
`hearing.threshold`	Age-related hearing threshold (ISO 7029:2017) and audiometric reference zero (ISO 389-7:2005).
`hearing.noise_induced_hearing_loss`	Estimation of noise-induced hearing loss (ISO 1999:2013).
`hearing.occupational_exposure`	Occupational noise exposure: measurement strategies and uncertainty (ISO 9612:2009).

Room acoustics

Module	Summary
`room.acoustics`	Room acoustic parameters from impulse responses per ISO 3382-1:2009 (performance spaces) and ISO 3382-2:2008 (ordinary rooms).
`room.impulse_response`	Impulse-response acquisition per BS EN ISO 18233:2006.
`room.noise_criteria`	Room-noise rating curves per ANSI/ASA S12.2-2019.
`room.open_plan`	Open-plan-office spatial metrics per ISO 3382-3:2012.
`room.reverberation_prediction`	Reverberation-time prediction from room geometry and absorption.
`room.enclosed_space_absorption`	Sound absorption in enclosed spaces (EN 12354-6:2003).
`room.image_source`	Synthetic room impulse response by the image-source method (rectangular room).
`room.steady_field`	Steady-state sound field in a room: room constant, critical distance, level.
`room.modes`	Normal modes of a rectangular room: frequencies, kinds, count and density.
`room.crowd_noise`	Crowd self-noise in a restaurant: the cocktail-party equilibrium.

Building acoustics

Module	Summary
`building.measurement.insulation`	Field measurement of sound insulation: airborne (ISO 16283-1:2014), impact (ISO 16283-2) and facade (ISO 16283-3:2016).
`building.measurement.ratings`	Single-number weighted ratings of sound insulation and their spectrum adaptation terms (ISO 717-1 airborne, ISO 717-2 impact).
`building.prediction.panel_transmission`	Predicted airborne sound reduction index of panels (Bies, Hansen & Howard 2017, Engineering Noise Control 5e, Section 7.2; Sharp 1973).
`building.prediction.masonry_cavity_wall`	Wall ties in masonry cavity walls: the structural bridge across the cavity (Hopkins 2007, Sections 3.11.3.2 and 4.3.5.4.1).
`building.measurement.heavy_impact`	Heavy and soft impact sources: rubber ball and bang machine (ISO 16283-2:2020 Annex A, ISO 10140-5:2010 Annex F, JIS A 1418-2:2019, ISO 717-2:2020 Annex D).
`building.prediction.ceiling_plenum`	Suspended-ceiling plenum flanking path (Vigran 9.2.3 after Mechel 1980; ISO 140-9 / ISO 10848-2; ASTM E1414 / ASTM E413).
`building.prediction.aperture_transmission`	Sound transmission through slits, holes and apertures (Hopkins 2007, Sound Insulation, Section 4.3.10; Gomperts 1964; Wilson & Soroka 1965).
`building.measurement.lab_insulation`	Laboratory sound insulation of building elements (ISO 10140).
`building.measurement.survey_insulation`	Field survey method for sound insulation and service-equipment noise (ISO 10052:2021).
`building.measurement.intensity_insulation`	Sound insulation measured with sound intensity (ISO 15186).
`building.measurement.flanking_transmission`	Laboratory measurement of flanking sound transmission (ISO 10848:2006/2010).
`building.prediction.facade`	Façade sound insulation and outdoor radiation prediction (EN 12354-3/-4:2000).
`building.prediction.simplified_model`	Building acoustic performance prediction (EN 12354-1/-2:2000).
`building.prediction.detailed_model`	Detailed per-band building prediction (EN/ISO 12354-1/-2:2017).
`building.measurement.uncertainty`	Measurement uncertainty in building acoustics (ISO 12999-1:2020).
`building.measurement.floor_covering_improvement`	Impact-sound improvement of floor coverings on a small mock-up (ISO 16251-1:2014).
`building.prediction.resilient_layers`	Prediction of resilient-layer performance: tapping force, floor coverings, floating floors.
`building.prediction.linings`	Prediction of wall and ceiling linings: the weighted improvement an additional layer gives the element behind it (ISO 12354-1:2017 Annex D).
`building.measurement.structure_borne_power`	Structure-borne sound power of building equipment (EN 15657:2018; ISO 9611).
`building.prediction.installed_structure_borne`	Installed structure-borne sound from service equipment (EN 12354-5:2009).
`building.regulation.spain`	Spanish building code CTE DB-HR: global indices and requirement checks.

Materials and surfaces

Module	Summary
`materials.absorbers.sound_absorption`	Sound absorption in a reverberation room: BS EN ISO 354:2003.
`materials.absorbers.rating`	Single-number rating of sound absorption (ISO 11654:1997).
`materials.absorbers.uncertainty`	Measurement uncertainty for sound absorption (ISO 12999-2:2020).
`materials.absorbers.airflow_resistance`	Airflow resistance of porous materials: ISO 9053-1 and ISO 9053-2.
`materials.resilient.dynamic_stiffness`	Dynamic stiffness of resilient materials under floating floors (EN 29052-1:1992).
`materials.absorbers.impedance_tube`	Two-microphone transfer-function method in the impedance tube.
`materials.absorbers.four_microphone`	Four-microphone transfer-matrix method for the transmission of a specimen.
`materials.absorbers.standing_wave`	Standing-wave-ratio method for normal-incidence absorption and impedance.
`materials.absorbers.porous`	Porous-material models and resonant sheet impedances.
`materials.absorbers.layered`	Declarative layer stacks and the transfer-matrix absorber solver.
`materials.absorbers.biot`	Biot poroelastic layers: the three waves and the 6x6 transfer matrix.
`materials.absorbers.slow_sound`	Slow-sound slit panels loaded with Helmholtz resonators (perfect absorbers).
`materials.diffusers.scattering_diffusion`	Directional and random-incidence diffusion coefficients in a free field.
`materials.diffusers.reverberation_room_scattering`	Random-incidence scattering coefficient in a reverberation room.
`materials.diffusers.design`	Far-field polar response and diffusion coefficient predicted from a diffuser design.
`materials.diffusers.metadiffuser`	Metadiffusers: deep-subwavelength Schroeder-like sound diffusers.
`materials.surfaces.road_absorption`	In-situ sound absorption of road surfaces (ISO 13472-1 / ISO 13472-2).

Vibration and structure-borne sound

Module	Summary
`vibration.structural.mechanical_mobility`	Mechanical mobility and the frequency-response-function family (ISO 7626-1:2011).
`vibration.structural.point_mobility`	Point mobilities and impedances of infinite structures (Cremer, Heckl & Petersson 2005, Chapter 5, Table 5.1).
`vibration.structural.radiation_efficiency`	Radiation efficiency of a plate in bending (Hopkins 2007, Sound Insulation, Section 2.9; Leppington et al.
`vibration.structural.junction_transmission`	Bending-wave transmission coefficients for rigid plate junctions (Hopkins 2007, Sound Insulation, Section 5.2.1.3; Cremer et al.
`vibration.structural.experimental_sea`	Experimental statistical energy analysis: coupling loss factors from measured energies (Norton & Karczub Ch.
`vibration.machinery.diagnostics`	Kinematic fault frequencies of rotating machinery (Norton & Karczub Ch.
`vibration.structural.transfer_stiffness`	Dynamic transfer stiffness of resilient elements (ISO 10846-1/-2/-3).
`vibration.human.exposure`	Human exposure to whole-body and hand-transmitted vibration.
`vibration.human.multiple_shock`	Whole-body vibration containing multiple shocks (ISO 2631-5:2018).

Environmental acoustics

Module	Summary
`environment.propagation.outdoor_propagation`	Outdoor sound propagation: ISO 9613-2:1996 general method of calculation.
`environment.sources.cnossos_road`	CNOSSOS-EU road traffic source emission (Directive 2002/49/EC Annex II, 2.2).
`environment.propagation.ground_barriers`	Spherical-wave ground effect and advanced barrier diffraction.
`environment.propagation.refraction`	Atmospheric refraction: ray tracing and the parabolic equation (PE).
`environment.propagation.air_absorption`	Atmospheric absorption of sound: ISO 9613-1:1993.
`environment.sources.cnossos_rail`	CNOSSOS-EU railway source emission (Directive 2002/49/EC Annex II, 2.3).
`environment.assessment.impulsive_sound`	Prominence of impulsive sounds and the `LAeq` adjustment (NT ACOU 112:2002, ISO/PAS 1996-3:2022).
`environment.assessment.rating`	Environmental noise descriptors per ISO 1996-1:2016.
`environment.sources.wind_turbine`	Wind-turbine acoustic noise (IEC 61400-11:2012+A1:2018).
`environment.assessment.measurement`	Determination of environmental-noise sound pressure levels (ISO 1996-2:2017).
`environment.assessment.spain`	Spanish noise regulation: the corrected level LKeq (Real Decreto 1367/2007).

Aircraft noise

Module	Summary
`aircraft.certification`	Aircraft noise certification: Effective Perceived Noise Level (ICAO Annex 16).
`aircraft.atmospheric_absorption`	One-third-octave-band atmospheric absorption for aircraft noise (SAE ARP 5534).
`aircraft.airport_noise`	Noise-Power-Distance (NPD) event-level interpolation (ECAC Doc 29).
`aircraft.anp_fleet`	EASA ANP fleet database bridge for the ECAC Doc 29 airport-noise chain.
`aircraft.rotorcraft_noise`	Rotorcraft noise by the hemisphere method (ECAC Doc 32 / NORAH2).
`aircraft.rotorcraft_propagation`	Rotorcraft propagation, ground effect and screening (ECAC Doc 32 / NORAH2).
`aircraft.measurement_system`	Aircraft-noise measurement-system tolerances (IEC 61265:1995).

Underwater acoustics

Module	Summary
`underwater.acoustics`	Underwater-acoustics reference levels (ISO 18405:2017).
`underwater.propagation.closed_form`	Underwater sound propagation: propagation loss (closed-form).
`underwater.propagation.weston_regimes`	Weston’s shallow-water propagation regimes (flux theory).
`underwater.propagation.sound_speed`	Speed of sound in sea water (empirical equations).
`underwater.sonar_equation`	The sonar equation (passive and active), in decibels.
`underwater.sources.ambient_noise`	Ocean ambient-noise spectrum levels (Wenz framework).
`underwater.propagation.seabed_reflection`	Plane-wave reflection at the seabed (fluid-fluid Rayleigh model).
`underwater.sources.ship_radiated_noise`	Ship radiated noise and equivalent monopole source level (ISO 17208-1/-2).
`underwater.sources.ship_traffic_noise`	Predicted source-level spectrum of shipping traffic (semi-empirical models).
`underwater.sources.pile_driving_noise`	Radiated underwater sound from percussive pile driving (ISO 18406:2017).
`underwater.bioacoustics.audiograms`	Marine-mammal hearing thresholds (group audiograms and the orca audiogram).
`underwater.bioacoustics.weighting`	Regulatory auditory weighting and exposure criteria for marine mammals.
`underwater.propagation.numerical`	Numerical models of underwater sound propagation (range-independent ocean).

Sound power and intensity

Module	Summary
`emission.sound_power`	Sound power level of a noise source from sound pressure measurements over an enveloping measurement surface: ISO 3744:2010 (engineering, accuracy grade 2) and ISO 3746:2010 (survey, accuracy grade 3).
`emission.sound_power_anechoic`	Sound power level of a noise source in an anechoic or hemi-anechoic room, from sound pressure measurements over an enveloping surface: ISO 3745:2012 (precision, accuracy grade 1).
`emission.sound_power_intensity`	Sound power level of a noise source by sound-intensity scanning: ISO 9614-2:1996 (engineering, grade 2; survey/control, grade 3) and ISO 9614-3:2002 (precision, grade 1).
`emission.sound_power_reverberation`	Sound power level of a noise source measured in a reverberation test room: ISO 3741:2010 (precision method, accuracy grade 1).
`emission.intensity`	Two-microphone (p-p) sound intensity per IEC 61043:1993 and the ISO 9614-1:1993 field indicators.
`emission.intensity_compliance`	IEC 61043:1993 sound-intensity instrument class verification.
`emission.vibration_sound_power`	Airborne sound power from surface vibration (ISO/TS 7849-1/-2:2009).
`emission.declaration`	ISO 4871:1996 declaration of noise emission values of machinery and equipment.

Electroacoustics

Module	Summary
`electroacoustics.distortion`	Harmonic distortion of electroacoustic equipment (IEC 60268-3 / AES17).
`electroacoustics.intermodulation`	Intermodulation distortion of audio equipment (IEC 60268-3 14.12.7-10).
`electroacoustics.noise_measurements`	Noise measurements of audio equipment (AES17-2015 6.4).
`electroacoustics.frequency_response`	Frequency-response and coherence estimators (Bendat & Piersol).
`electroacoustics.swept_sine`	Harmonic-distortion separation with exponential sweeps (Farina / Novak).
`electroacoustics.piston`	Radiation of a rigid circular piston set in an infinite baffle.
`electroacoustics.loudspeaker`	Rated loudspeaker characteristics (IEC 60268-5).
`electroacoustics.microphone`	Rated microphone characteristics (IEC 60268-4).
`electroacoustics.sound_reinforcement`	Gain before feedback of a sound-reinforcement system.

Industrial noise control

Module	Summary
`noise_control.silencers`	Reactive silencers by the four-pole (transmission-matrix) method.
`noise_control.hvac`	HVAC duct acoustics: fan power, duct losses, plenums and flow-generated noise.
`noise_control.duct_path`	End-to-end duct-borne noise calculation: fan to room, element by element.
`noise_control.duct_modes`	Higher-order acoustic modes in ducts, with the mean-flow cut-on shift.
`noise_control.enclosures`	Insertion loss of a close or free-standing machine enclosure.
`noise_control.room_to_room`	Room-to-room noise reduction: source room, partition, receiving room, criterion.

Program loudness

Module	Summary
`broadcast.program_loudness`	Programme loudness and true-peak level (ITU-R BS.1770-5, EBU R 128).

Wave simulation

Module	Summary
`simulation.fdtd`	2D acoustic finite-difference time-domain (FDTD) simulation.
`simulation.ntff`	2D near-to-far-field (NTFF) transformation over a closed contour.
`simulation.elastic_fdtd`	2D elastic finite-difference time-domain (P-SV) simulation.

Created and maintained by José Manuel Requena Plens ORCID All projects