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.

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

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, 468, 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.time_invariance	The exponential-sweep test of a band filter: time-invariant operation.
filters.periodic_tests	Periodic tests of band filters (IEC 61260-3:2016): test frequencies and verdict.
filters.weighting_compliance	IEC 61672-1:2013 frequency-weighting class verification.

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.

Module	Summary
metrology.calibration	Calibration utilities for mapping digital signals to physical SPL levels.
metrology.sound_calibrator	Sound calibrators (IEC 60942:2017): the class tables and the verdict on one.
metrology.conformance	The conformance rule of IEC TC 29: a deviation, its limits and its uncertainty.
metrology.uncertainty	Measurement uncertainty by the GUM and its Monte Carlo supplement.
metrology.data_qualification	Random-data qualification: stationarity tests and Rice crossing statistics.
metrology.reference_values	Preferred reference values for acoustical and vibratory levels (ISO 1683:2015).
metrology.random_incidence	Random-incidence and diffuse-field sensitivity of a sound level meter (IEC 61183:1994).
metrology.free_field_corrections	Corrections that bring a sound level meter to its free-field response (IEC 62585:2012).

Module	Summary
fluids	fluids domain of phonometry (see module docstrings).
fluids.air	Humid air (IEC 61094-2:2009, Annex F).
fluids.gas	An ideal gas from the two numbers a gas table prints.
fluids.water	Sea water: its speed of sound, and its density.
fluids.catalogue	Fluid states read from a printed page.
fluids.nonlinearity	The nonlinearity parameter B/A of liquids, as a handbook tabulates it.

Module	Summary
solids.elastic	Three longitudinal wave speeds of a solid, and which one a table prints.
solids.catalogue	Solid materials as one published table prints them.
solids.damping	Commercial damping materials, with the temperature and the frequency.
solids.damping_treatments	Damping treatments rated by the decay rate of a treated panel.
solids.nonlinearity	The nonlinearity parameter of solids, as a handbook tabulates it.
solids.orthotropic_wood	Wood, which is not the same material in two directions.
solids.plateau	The three numbers a panel needs before its transmission loss can be sketched.

Module	Summary
io	Measurement audio files: read, write, stream and convert without touching a level.

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.

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).

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).
hearing.real_ear_attenuation	Real-ear attenuation of a hearing protector and its uncertainty (ISO 4869-1:2018).
hearing.hearing_protectors	What a hearing protector leaves at the ear (ISO 4869-2:2018).
hearing.active_noise_reduction	Total attenuation of an active noise reduction earmuff (ISO 4869-6:2019).

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.auditorium	Auditorium measures derived from impulse responses (ISO 3382-1:2009, Annex A).
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.
room.spatial_decay	Spatial sound distribution curves in workrooms (ISO 14257:2001).
room.workroom_prediction	Predicting sound propagation in a workroom (ISO 11690-3:1998).

Module	Summary
building.measurement.insulation	Field measurement of sound insulation: airborne (ISO 16283-1:2014), impact (ISO 16283-2:2020) and facade (ISO 16283-3:2016).
building.measurement.low_frequency	Low-frequency procedure of ISO 16283, shared by all three parts.
building.measurement.ratings	Single-number weighted ratings of sound insulation and their spectrum adaptation terms (ISO 717-1 airborne, ISO 717-2 impact).
building.catalogue	Transmission loss as the books print it, one row per construction.
building.impact_catalogue	Impact insulation as a handbook prints it, one row per floor-ceiling.
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.

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.resilient.moduli	The dynamic modulus of resilient materials, as a textbook tabulates it.
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.catalogue	Porous specimens as the pages that print them have them.
materials.absorbers.resistive_sheets	Thin resistive facings, and the resistance of one square metre of them.
materials.absorbers.measured	Absorption coefficients as the books print them, one row per finish.
materials.absorbers.carpets	Carpets, rated by their noise reduction coefficient and described by their pile.
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.absorbers.suspended_ceilings	Suspended ceilings in a reverberation room: EN 16487:2014.
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.diffusers.measured_scattering	Scattering coefficients as the books print them, one row per surface.
materials.diffusers.predicted_diffusion	Normalized diffusion coefficients as a book computes them, one row per angle.
materials.diffusers.predicted_scattering	Scattering coefficients a book computed, kept apart from the ones measured.
materials.surfaces.road_absorption	In-situ sound absorption of road surfaces (ISO 13472-1 / ISO 13472-2).

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.machinery.evaluation	Evaluation of machine vibration by measurement (ISO 20816-1:2016).
vibration.structural.transfer_stiffness	Dynamic transfer stiffness of resilient elements (ISO 10846, Parts 1 to 5).
vibration.structural.building_damage	Effects of vibration on structures (DIN 4150-3:1999-02).
vibration.structural.building_response	Predicting the fundamental frequency of a building (ISO 4866 Annex D).
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).
vibration.human.seat_vibration	What a seat does to the vibration under it (ISO 10326-1:2016).
vibration.human.instrumentation	Type-testing a human-vibration meter against ISO 8041-1:2017.
vibration.human.signal_burst	The saw-tooth signal burst of ISO 8041-1:2017, 5.9, and what a meter reads.
vibration.immission.vibration_meter	The vibration meter of DIN 45669-1:2010-09 (with Corrigendum 1:2012-12).
vibration.immission.railway	Evaluating the vibration of a passing train (DIN 45672-2:1995-07).
vibration.immission.ground	The elastic properties of the ground from its wave speeds (DIN 45672-1:2009-12).
vibration.immission.coupling	Mounting the transducer, and what the meter may be wrong by (DIN 45669-2:2005-06).
vibration.immission.people	Vibration and the people in a building (DIN 4150-2:1999-06).
vibration.immission.train_categories	Railway vibration by category of train (E DIN 4150-2:2023-08, 6.5.3).
vibration.immission.railway_prediction	Predicting railway vibration from third-octave spectra (E DIN 45672-3:2023-02).
vibration.immission.prediction	Predicting vibration before it is measured (DIN 4150-1:2001-06).

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.sources.statistical_pass_by	What a road surface adds to the noise of the traffic on it (ISO 11819-1:1997).
environment.propagation.ground_barriers	Spherical-wave ground effect and advanced barrier diffraction.
environment.propagation.ground_surfaces	Ground surfaces as the pages that print them print them.
environment.propagation.noise_reducing_devices	Single-number ratings of noise reducing devices (EN 1793, EN 16272).
environment.propagation.barrier_in_situ	What a barrier by the road is worth, measured (ISO 10847:1997).
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.exposure_distribution	How often a blast is how loud: the distribution of its sound exposure level (ISO 13474:2009, clauses 4 and 5).
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).
environment.assessment.soundscape	How people hear a place: the soundscape questionnaire and its analysis (ISO/TS 12913-2:2018 Annexes A and C, ISO/TS 12913-3:2019 Annexes A and B).
environment.assessment.soundscape_binaural	What a soundscape sounds like at the ears: the binaural analysis of ISO/TS 12913-3:2019 Annex D and ISO/TS 12913-2:2018 Annex D.

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.flight_performance	ECAC Doc 29 flight performance: procedural steps into a flight profile.
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).

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	Sound-speed profiles over a column of water.
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 water, with an optionally sloping bottom for the ray-based solvers).

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_intensity_points	Sound power level of a noise source from sound intensity measured at discrete points: ISO 9614-1:1993.
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.sound_power_in_situ	Sound power and sound energy levels of a noise source determined in situ by comparison with a reference sound source: ISO 3747:2010 (engineering grade 2 and survey grade 3).
emission.sound_power_in_duct	Sound power radiated into a duct by a fan, in-duct method: ISO 5136:2003.
emission.sound_power_high_frequency	Sound power levels in the 16 kHz octave band: ISO 9295:2015.
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.workstation	What the ISO 11200 group shares: the emission sound pressure level at a work station, its two corrections and its uncertainty.
emission.declaration	ISO 4871:1996 declaration of noise emission values of machinery and equipment.

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.

Module	Summary
noise_control.silencers	Reactive silencers by the four-pole (transmission-matrix) method.
noise_control.silencer_measurement	Insertion loss of a ducted silencer, measured by substitution.
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.duct_walls	What a duct wall does to sound, out of it and into it.
noise_control.enclosures	Insertion loss of a close or free-standing machine enclosure.
noise_control.enclosure_insulation	What an enclosure is worth, measured rather than predicted (ISO 11546).
noise_control.cabin_insulation	What a cabin keeps out, measured in the room it stands in (ISO 11957).
noise_control.silencer_in_situ	What a silencer does where it was installed (ISO 11820:1996).
noise_control.screen_in_situ	What a screen on the shop floor is worth (ISO 11821:1997).
noise_control.room_to_room	Room-to-room noise reduction: source room, partition, receiving room, criterion.
noise_control.valves	Control valve aerodynamic noise (IEC 60534-8-3:2010).
noise_control.valves_hydrodynamic	Control valve hydrodynamic noise (IEC 60534-8-4:2005).

Module	Summary
broadcast.program_loudness	Programme loudness and true-peak level (ITU-R BS.1770-5, EBU R 128).
broadcast.quasi_peak	Psophometric quasi-peak programme-level meter (ITU-R BS.468-4 clause 2).

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.