Acoustics Tools
Browse all available acoustics tools.
Available tools
- A-Weighting Correction Lookup Standardnominal A weightingtransfercorrectiondB fromactualpositivefrequency,not fullspectrumweightedLeq or calibratedinstrumenttolerance. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Absorption Required For Target Rt Metric Sabine equivalent absorption area required for a target RT60: 0.161V/T.
- Absorption Required for Target RT Practice Create reproducible practice for Absorption Required for Target Rt from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Absorption Standard Cross-Reference Distinguish ISO 354 and ASTM C423 report context without inventing a universal result conversion.
- Acoustic Impedance Medium Characteristic specific acoustic impedance rho*c for a uniform medium.
- Acoustic Impedance Medium Practice Create reproducible practice for Acoustic Impedance Medium from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Acoustic Intensity From Spl Plane-wave free-field intensity from sound-pressure level, assuming the conventional 10^-12 W/m² reference.
- Acoustic Intensity from SPL Practice Create reproducible practice for Acoustic Intensity from SPL from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Acoustic Power From Intensity Area Acoustic power crossing an area under uniform normal incidence.
- Acoustic Power from Intensity Area Practice Create reproducible practice for Acoustic Power from Intensity Area from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Acoustic Sharpness Reference Return the definition, unit, reference sound, and interpretation cautions for psychoacoustic sharpness.
- Air Absorption Loss Atmospheric attenuation in dB from a specified frequency-dependent attenuation coefficient and path distance.
- Air Absorption Loss Practice Create reproducible practice for Air Absorption Loss from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Airgun Soft-Start Reference Return the purpose and project-specific nature of seismic-airgun ramp-up mitigation.
- Amplitude Modulation Depth Calculate peak-to-trough sound-level modulation depth and compare it with an explicit caller threshold; this is not a full regulatory OAM method.
- Angular Frequency Calculator Angular frequency in radians per second from frequency in hertz.
- Angular Frequency Practice Create reproducible practice for Angular Frequency Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Apparent Sound Reduction Index Calculator ActualapparentreductionindexR′=L1−L2+10log10(S/A),matchedband;flankingincludedinactualmeasurement,no isolatingtruepartitionR. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Area Weighted Absorption Coefficient Area-weighted mean absorption coefficient of two surface materials.
- Area Weighted Absorption Coefficient Practice Create reproducible practice for Area Weighted Absorption Coefficient from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Area Weighted Composite STC Calculator Qualified caller-reference retrieval for Area Weighted Composite STC Calculator. Independently applicable actual frequency-bandpartitionareatransmissioncurve/junction/flanking and applicableASTME413ratingedition;cannot compute trueSTCby averagingSTCnumbers. Does not compute omitted scientific/design/predictive models or publish authoritative complete tables. Source truth and applicability external;examples illustrative. No diagnosis,compliance,identity determination,safe-use approval or guaranteed forecast.
- ASA Committee Scope Reference Return a dated map of selected Acoustical Society of America technical-committee scopes.
- ASTC Field-Rating Reference Distinguish apparent field sound-transmission ratings from laboratory STC without offering a false fixed conversion.
- ASTM C423 Method Reference Return the purpose and key reporting cautions of the ASTM reverberation-room absorption method.
- Audience Absorption Reference Explain how occupied-audience equivalent absorption must be selected and documented without publishing a universal per-person table.
- Auralization Process Reference Return the impulse-response convolution and binaural-rendering stages of acoustic auralization.
- Axial Mode Frequency Rectangular-room axial mode frequency along one dimension for a positive integer mode order.
- Background Correction Applicability Classify source-plus-background separation for energetic correction: under 3 dB invalid, 3–10 dB correction range, and at least 10 dB negligible correction.
- Balanced Noise Criterion Reference Explain the revised balanced-noise-criterion method and its relationship to other room-noise ratings.
- Band Edge Frequencies Calculator Exactbase2fractionaloctavebandedges,not base10IECpreferredfrequency rounding. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Band Loudness Aggregation Combine a dominant band loudness with the sum of other bands using an explicit coupling factor; this does not claim the complete Stevens Mark VI procedure.
- Band Loudness Aggregation Practice Create reproducible practice for Band Loudness Aggregation from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Bark Band Converter DeclaredZwickerBarkcoordinateapproximationz(f),0≤f≤20kHz,not frequencybinindexormel. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Barrier Path Difference Extra diffracted sound-path length around a barrier versus direct line-of-sight distance.
- Barrier Path Difference Practice Create reproducible practice for Barrier Path Difference from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Bass Ratio Calculate (T125 + T250) / (T500 + T1000) from caller-supplied reverberation times; interpretation remains project-specific.
- Beats Frequency Beat rate in hertz from the absolute frequency difference of two close tones.
- Beranek Concert Hall Reference Return the scope and cautions of Leo Beranek’s concert-hall studies and ratings.
- Binaural Unmasking Reference Distinguish head-shadow level effects from binaural masking-level differences.
- Brilliance Ratio Calculate (T2000 + T4000) / (T500 + T1000) from caller-supplied reverberation times; interpretation remains project-specific.
- Bulk Modulus From Sound Speed Adiabatic bulk modulus rho*c² from medium density and sound speed.
- Bulk Modulus from Sound Speed Practice Create reproducible practice for Bulk Modulus from Sound Speed from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- C-Weighting Correction Lookup Standardnominal C weightingtransfercorrectiondB fromactualpositivefrequency,not fullspectrumweightedLeq or calibratedinstrumenttolerance. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Calibration Drift Screen Calculate absolute before-versus-after sound-calibrator drift and compare it with an explicit acceptance limit.
- Calibration Level Offset Signed level calibration offset to add to measured readings to match a reference calibrator.
- Calibration Level Offset Practice Create reproducible practice for Calibration Level Offset from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Ceiling Hanger Layout Screen Estimate a rectangular hanger grid and compare total rated capacity with a caller-supplied ceiling load; structural design remains outside this screening calculation.
- Cents To Ratio Converter Frequency ratio corresponding to a signed interval in cents.
- Cents to Ratio Practice Create reproducible practice for Cents to Ratio Converter from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Circular Membrane Fundamental Calculator IdealclampedcircularmembraneaxisymmetricfundamentalfromfirstJ0zero,radiusnotdiameter,not flexuralplate. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Clamped Bar Fundamental Calculator RestrictedEuler–BernoulliuniformFIXED-FREEcantileverfundamental,β1≈1.8751040687,not both-endclamped/torsion/shortthickbar. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Classroom Background-Noise Screen Compare an unoccupied furnished classroom background level with a caller-supplied limit; 35 dBA, not 30 dBA, is the common ANSI/ASA S12.60 design value for typical core learning spaces.
- CNEL Community Noise Equivalent Calculator DeclaredCaliforniaCNEL12day3evening9night hourwindows,+5/+10dBpenalties,allactualLeqwindowscomplete,noconflateLden16/8 convention. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Combination Tone Sum Sum combination-tone frequency from two input sinusoid frequencies.
- Concert Hall Geometry Screen Screen volume per seat and ceiling height against explicit caller-supplied ranges rather than universal hall norms.
- Concert Hall Shape Reference Compare broad shoebox, vineyard, and fan-shaped hall geometry without ranking a shape independently of detailed design.
- Concert Hall Volume per Seat Calculate room volume per audience seat from caller-supplied hall volume and seat count; no universal benchmark is asserted.
- Coupled Room Volume Screen Screen caller-supplied coupled-volume and opening ratios against explicit project thresholds without claiming a universal coupled-room criterion.
- Critical Band Width Lookup Qualified caller-reference retrieval for Critical Band Width Lookup. Independently applicable actual frequency/listeninglevel/author/critical-banddefinition and independentlymatched auditorybandwidthreference. Does not compute omitted scientific/design/predictive models or publish authoritative complete tables. Source truth and applicability external;examples illustrative. No diagnosis,compliance,identity determination,safe-use approval or guaranteed forecast.
- Critical Distance Diffuse-field critical distance sqrt(QR/16π) from source directivity and room constant R in m².
- Day Night Level Dnl 24-hour day-night level from representative 15-hour day and 9-hour night Leq, with a 10 dB night penalty.
- Day-Evening-Night Level Calculate Lden from 12-hour day, 4-hour evening, and 8-hour night Leq values with 5 dB and 10 dB penalties.
- Db Addition Two Sources Energetic sum of two uncorrelated sound levels in decibels.
- Db Mean Of Readings Energetic mean, not arithmetic mean, of two equal-duration sound-level readings.
- Db Subtract Background Source-only sound level after energetic subtraction of measured background from total level.
- Decay Rate Db Per Second Average dB-per-second level decline from an RT60 time interval.
- Derated NRR OSHA Calculator DeclaredOSHA-style50%deratedA-weightedNRRadjustmentmax(0,(NRR−7)/2),not fittingcertification/earlevel/safehearinglimit. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Difference Tone Frequency Absolute difference combination-tone frequency from two input sinusoid frequencies.
- Direct To Reverberant Ratio Ideal direct-to-reverberant sound-energy ratio in dB at distance r, using Q R/(16πr²).
- Distance Doubling Decibel Drop Free-field point-source level reduction in dB after a given number of distance doublings.
- DNL Segment Level Solver Solve the standard 15-hour day or 9-hour night Leq from DNL and the other segment, retaining the 10 dB night penalty.
- Doppler Approaching Frequency Observed frequency from a source approaching a stationary listener through still air.
- Doppler Receding Frequency Observed frequency from a source receding from a stationary listener through still air.
- Doppler Ultrasound Shift Signed pulse-echo Doppler shift 2 f0 v cos(theta)/c for tissue velocity at angle theta.
- Double-Slope Decay Screen Compare positive early and late decay-rate magnitudes against an explicit fractional-change threshold.
- Early Lateral Energy Fraction Calculate the early lateral-energy fraction from caller-supplied 5–80 ms lateral and 0–80 ms omnidirectional energies.
- Echo Ranging Distance Reflector distance from round-trip echo time and propagation speed.
- EDT and Late-Decay Reference Distinguish early decay time from later reverberation-time regressions defined by ISO 3382.
- Equivalent Continuous Level Leq Two-interval equivalent continuous sound level from each interval's level and duration.
- FAA Part 150 Land-Use Reference Return federal airport-noise compatibility context without replacing the full land-use table or local planning decision.
- FEM and BEM Domain Reference Compare low-frequency acoustic finite- and boundary-element method domains without selecting a solver from frequency alone.
- Festival Noise Limit Screen Compare an offsite measured level plus explicit positive uncertainty with a caller-supplied limit.
- FHWA Noise Abatement Reference Return the federal highway-noise criterion context for common receptor categories.
- Flanking Junction Record Lookup Look up a caller-supplied wall, floor, or ceiling junction detail, report its documented ratings and any direct-versus-apparent difference, and avoid universal flanking corrections.
- Floor Footfall Frequency Screen Screen the separation between a floor natural frequency and a caller-supplied forcing frequency; it is not a full AISC Design Guide 11 response analysis.
- Fluctuation Strength Reference Return the modulation-rate context and limitations of psychoacoustic fluctuation strength.
- Flutter Echo Frequency Calculate the round-trip interval and repetition frequency between parallel surfaces under a caller-supplied sound speed.
- Frequency From Wavelength Acoustic frequency from wave speed and positive wavelength.
- Fresnel Number Barrier Barrier Fresnel number 2δ/λ from extra sound-path length and wavelength.
- FTA Vibration Criterion Screen Compare residential maximum vibration velocity level with the FTA Category 2 criterion for frequent, occasional, or infrequent events.
- Gas Sound Speed Gamma Ratio Ideal-gas sound speed sqrt(gamma*R*T/M) from heat-capacity ratio, Kelvin temperature and molar mass.
- Ground Reflection Two Ray Calculator Restrictedcoherenttwo-rayrealreflection sphericalspreadingpathinterference,not fullfrequencydependentcomplexgroundimpedance/nearfield. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Haas Precedence Window Lookup Qualified caller-reference retrieval for Haas Precedence Window Lookup. Independently applicable actual stimulus/room/listener/delaylevelratio and independently measuredHaasprecedencewindow. Does not compute omitted scientific/design/predictive models or publish authoritative complete tables. Source truth and applicability external;examples illustrative. No diagnosis,compliance,identity determination,safe-use approval or guaranteed forecast.
- Half Wave Resonator Length Ideal half-wave resonator length from sound speed and fundamental frequency, before end correction.
- Hearing Protection NRR to dBA Calculator DeclaredUSscreen dBA−(NRR−7),actualapplicableNRR/fitexternal,not guaranteedprotectedearlevelor authorize exposure. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Helmholtz Port Length Physical Helmholtz neck length required for a target resonance, subtracting a supplied total end correction.
- Helmholtz Resonance Frequency Lumped Helmholtz resonator frequency from sound speed, neck area, cavity volume and effective neck length.
- HUD Noise Site Reference Return HUD environmental-noise site categories and procedural cautions.
- Hz To Mel Converter Frequency in mels from hertz using the common 2595 log10(1+f/700) scale.
- IEC 61672 Class Reference Return the practical distinction and limitations of Class 1 and Class 2 sound-level meters.
- IIC Floor Assembly Lookup Select a caller-supplied floor assembly by identifier and minimum ASTM E989 IIC while preserving the exact floor, covering, underlayment, test method, and rating provenance.
- Image-Source Method Reference Return the geometric construction and limitations of the room-acoustic image-source method.
- Intensity Level From Intensity Sound-intensity level in dB relative to 10^-12 W/m².
- Interval Ratio To Cents Musical interval in cents from a positive frequency ratio.
- Inverse Square Law Level Change Free-field point-source sound-level change in dB when observation distance changes from r1 to r2.
- ISO 2631 Weighting Reference Return whole-body-vibration weighting and axis-selection cautions.
- ISO 3382 Part Reference Map the principal scopes of ISO 3382 Parts 1, 2, and 3.
- ISO 9613-2 Attenuation Reference Return the principal outdoor sound-propagation attenuation terms and method cautions.
- ISO TC 43 Scope Reference Return a dated high-level scope of ISO/TC 43 and its acoustics subcommittees.
- Isolator Static-Deflection Screen Calculate the idealized vertical natural frequency from static deflection and compare it with an explicit caller maximum; real isolator selection still requires load and manufacturer data.
- Knudsen Curve Reference Return the historical scope of Knudsen-era ocean ambient-noise spectra.
- Layered Gypsum Wall STC Lookup Select the highest-rated caller-supplied layered gypsum wall assembly matching framing, identifier, and minimum-STC filters while preserving laboratory, manufacturer, and test-report provenance.
- Leaf-Blower Tonality Reference Return measurement cautions for low-frequency and tonal leaf-blower noise without assigning annoyance from a device label.
- Leq Sample-Duration Screen Compare an actual equivalent-level sample duration with an explicit protocol minimum; no universal minimum duration is assumed.
- Listed Assembly Evidence Reference Return evidence checks for a listed acoustic or fire-rated assembly without claiming that a listing supplies a universal flanking correction.
- Localization ILD Threshold Lookup Qualified caller-reference retrieval for Localization ILD Threshold Lookup. Independently applicable actual stimulusfrequency/level/binauralconditions/individualtest and independently measuredILDthreshold. Does not compute omitted scientific/design/predictive models or publish authoritative complete tables. Source truth and applicability external;examples illustrative. No diagnosis,compliance,identity determination,safe-use approval or guaranteed forecast.
- Localization Itd Max Delay Simple maximum interaural time difference in microseconds using a straight ear-to-ear baseline and sound speed.
- Lothar Cremer Room-Acoustics History Return documented areas of Lothar Cremer’s acoustics contributions.
- Mach Angle Shock Wave Mach angle in degrees asin(1/M) for supersonic Mach number.
- Marine Mammal Hearing Group Reference Return the purpose and limitations of regulatory marine-mammal hearing groups.
- Mass Law Transmission Loss Approximate random-incidence mass-law transmission loss in dB for a thin homogeneous panel below coincidence: 20log10(surface mass × frequency) −47.
- McGurk Effect Reference Return the audiovisual speech-conflict phenomenon and experimental cautions.
- Measurement Time Weighting Lookup Bounded offline reference: NominalF/Ssoundmeter timeweightingreference. Only explicit listed topics;not exhaustive/live data or diagnosis,safety/compliance/identity certificate.
- Mel To Hz Converter Frequency in hertz from mels using the inverse of the 2595-log mel scale.
- Microphone Incidence Reference Return free-field and random-incidence microphone response context.
- Microphone Placement Reference Return placement controls for reducing local surface-reflection bias in environmental measurements.
- Missing Fundamental Reference Return the pitch mechanism and limitations of the missing-fundamental phenomenon.
- MLV Product STC Lookup Look up a provenance-bearing MLV product row, convert its surface mass to metric units, and explicitly avoid treating a standalone specimen STC as an additive assembly supplement.
- Modal Density High Frequency Calculator Leadingvolume Weylhigh-frequencyroommodaldensitydN/df=4πVf²/c³,omittedsurface/edgecorrections,not exactlowfrequencymode enumeration. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Moving Observer Frequency Shift Observed frequency for a listener moving toward a stationary source through still air.
- Music Clarity C80 Calculate C80 as 10 log10 of early-to-late squared-impulse-response energy.
- Music Clarity C80 Practice Create reproducible practice for Music Clarity C80 from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Noise Exposure Forecast Calculator Calculate the legacy U.S. Noise Exposure Forecast from an energy-averaged EPNL and caller-supplied daytime and nighttime operation counts, with the historical 16.7 night weighting and an 88 dB offset.
- Noise Metric Sel From Event Leq Sound exposure level from event Leq and measured event duration relative to one second.
- NRC From Band Coefficients Calculator DeclaredNRCroundednearest0.05meanactual4bandabsorptionat250/500/1000/2000Hz;not allfreqSAA or roomreverberation. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Oblique Mode Frequency Rectangular-room mode frequency for three nonzero axial orders and dimensions.
- Octave Band Centers Ideal octave-band center frequency relative to a reference frequency and signed integer band offset.
- Octave Illusion Reference Return the two-channel pattern and localization cautions of Deutsch’s octave illusion.
- OITC Reference Return the scope and traffic-noise relevance of Outdoor-Indoor Transmission Class.
- One-Decibel JND Reference Return the nominal 1 dB level-difference reference with the psychophysical conditions required before it can be called a just-noticeable difference.
- Open Pipe Fundamental Ideal first resonance of a pipe open at both ends, neglecting end corrections.
- Orchestra Reflector Reference Return design controls for orchestra shells and overhead reflectors without inventing universal height or angle settings.
- Ordinance Hours Screen Check a same-day activity interval against caller-supplied ordinance hours, with an explicit variance override; it embeds no jurisdictional schedule.
- Parabolic Focus Screen Calculate the focal distance of a parabolic section from aperture width and depth and screen an occupied location against an explicit focus-zone radius.
- Particle Velocity From Pressure Particle velocity amplitude for a traveling plane wave from pressure amplitude and characteristic impedance.
- Percentile Statistical LN Level Calculator Actualequal-windowLnexceededpercent nearest-rankempiricalquantile,not logarithmicmean/genericpercentilewithoutdirection. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Peutz ALcons Estimate Apply the simplified Peutz far-field estimate 200 r² T60²/(VQ), preserving the uncapped result and a 100-percent display cap.
- Phon To Sone Converter Loudness in sones from phon level for 40 phon or above: 1 sone at 40 phon, doubling every 10 phon.
- Pipe End Correction Approximate unflanged open-pipe end correction 0.61 times the pipe radius, per open end.
- Practice-Room Noise Target Screen Compare a measured room-criterion value with an explicit caller target while preserving the caller’s instrument-family label.
- Pulse Repetition Range Ambiguity Maximum unambiguous pulse-echo range c/(2·PRF) for propagation speed and pulse repetition rate.
- Pythagorean Comma Value Calculator Pythagoreancomma(3/2)^12/2^7=531441/524288incents,independentnumberofcommas,signedcountallowed. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Quarter Wave Resonator Length Ideal quarter-wave resonator length from sound speed and fundamental frequency, before end correction.
- Railway Pass By Sel Sound exposure level from a pass-by Leq and event duration relative to one second.
- Range Shadow-Zone Verification Compare a predicted shadow-zone transition with a measured transition interval and explicit tolerance; this does not certify projectile containment or range safety.
- Resilient Channel STC Comparison Look up the caller-supplied STC change from direct board attachment to a specified resilient-channel assembly, preserving channel, spacing, test, and manufacturer caveats.
- Room Criterion Reference Distinguish RC-family ratings and diagnostic descriptors without reproducing proprietary or edition-specific tables.
- Room Mean Free Path Diffuse-field mean free path 4V/S inside a room from volume and total surface area.
- Room Simulation Engine Reference Compare broad capabilities of established geometric room-acoustics engines without claiming result equivalence.
- Room Volume From Dimensions Rectangular room volume from internal length, width and height.
- Room-Type RT60 Reference Return cautious room-type reverberation-time design context without asserting a universal numeric target.
- Roughness 70 Hz Reference Return the documented 70 Hz maximum of the 1-asp roughness reference while distinguishing that demonstration from a universal prediction.
- Sabine and Fogg Lecture Hall History Return sourced milestones in Sabine’s Fogg Lecture Hall work and reverberation research.
- Scale Model One To Ten Times Ten Frequency Rule Frequency required in a geometrically reduced 1:N acoustic scale model to represent a full-scale frequency.
- Schroeder Decay Method History Return the historical contribution and scope of Schroeder’s integrated-impulse-response decay method.
- Schroeder Frequency Approximate Schroeder transition frequency 2000 sqrt(RT60/V) for room volume in m³ and reverberation time in seconds.
- Seat Absorption Delta Calculate the signed occupied-minus-empty equivalent absorption for a seating sample and per seat.
- Semitone Offset Frequency Frequency after a signed number of semitones in 12-tone equal temperament.
- Shepard Tone Reference Return the construction and perceptual limitation of the Shepard-tone pitch-class illusion.
- Sonar Stranding Evidence Reference Return a cautious evidence framework for naval-sonar and beaked-whale stranding context.
- Sone To Phon Converter Phon level from loudness of at least one sone, using 40+10 log2(sones).
- Sound Energy Density Acoustic energy density of a traveling plane wave from intensity divided by propagation speed.
- Source Array Db Increase Free-field energetic level increase in dB from N independent equal-strength incoherent sources.
- Space Noise Criteria Reference Return room-noise criterion selection cautions for occupied spaces.
- Specific Loudness Reference Return the role of critical-band rate in the Zwicker loudness model.
- Speech Clarity C50 Calculate C50 as 10 log10 of early-to-late squared-impulse-response energy.
- Speech Clarity C50 Practice Create reproducible practice for Speech Clarity C50 from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
- Speech Interference Level Arithmetic mean of speech-band octave levels at 500, 1000, 2000 and 4000 Hz.
- Speech Privacy Class Screen Add average level difference and average background level as the ASTM E2638 speech-privacy potential and compare it with an explicit target SPC.
- Speech SNR Screen Calculate speech-to-noise level difference and compare it with an explicit caller-supplied minimum.
- Speech Transmission Index Method Reference Summarize the scope and limitations of the standardized STI method.
- Speech-to-Song Reference Return the repetition-based speech-to-song illusion and its limitations.
- Speed Of Sound Air Temperature Approximate dry-air sound speed in m/s from Celsius temperature using 331.3+0.606T; intended for ordinary ambient conditions.
- Speed of Sound in Seawater Calculator Qualified piecewise-linear calibration for Speed of Sound in Seawater Calculator. Actual samepressure/salinityseawatertemperature-soundspeedmeasurements,no purewaterpolynomialunqualifiedseawaterreuse. Increasingmatchedknots,noextrapolation,no universalcurve or fit. Examplesillustrative,actualsource independently verified;no safe-use approval or validated forecast.
- Speed of Sound in Water Calculator Restricted purewaterMarczaktemperaturepolynomialm/satnearambientpressure,0≤T≤40C,not generalpressure/salinitymodel. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Standing Wave Node Spacing Distance between adjacent nodes of a standing wave from its wavelength.
- STC and NIC Metric Classifier Classify a caller-supplied ASTM or ISO airborne-sound record as laboratory STC, field NIC, apparent ASTC, or the corresponding distinct rating without equating the metrics.
- Stevens Power Exponent Lookup Qualified caller-reference retrieval for Stevens Power Exponent Lookup. Independently applicable actual namedpsychophysicalstimulus/modality/experiment/intensitybasis and independently measured Stevenspowerexponent. Does not compute omitted scientific/design/predictive models or publish authoritative complete tables. Source truth and applicability external;examples illustrative. No diagnosis,compliance,identity determination,safe-use approval or guaranteed forecast.
- STI Edition History Return dated IEC 60268-16 edition context without treating editions as numerically interchangeable.
- STI to CIS Convert a positive Speech Transmission Index to Common Intelligibility Scale using CIS = 1 + log10(STI).
- Stopped Pipe Fundamental Ideal first resonance of a pipe stopped at one end, neglecting end corrections.
- String Tension For Target Pitch Tension needed for an ideal stretched string to reach a target fundamental frequency.
- Stud Wall STC Comparison Compare a caller-supplied single-stud and double-stud laboratory STC pair, return the signed point difference, and preserve each test reference without treating the result as a universal construction rule.
- Syntonic Comma Value Calculator Syntoniccomma81/80incents,independentnumberofcommas,signedcountallowed. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Tangential Mode Frequency Rectangular-room mode frequency for two nonzero axial mode orders and dimensions.
- Temporal Integration Gain Ideal energy-integration gain in dB from increasing coherent observation duration; excludes auditory saturation.
- Third Octave Band Centers Ideal third-octave-band center from a reference frequency and signed integer third-octave offset.
- Tissue Attenuation Frequency Loss Pulse-echo attenuation in dB from a specified tissue coefficient, transducer frequency, and one-way depth.
- Tone Prominence Ratio Calculate a tone-minus-masking-noise prominence ratio and compare it with an explicit caller threshold; a complete ECMA tonal analysis requires band-specific processing.
- Total Absorption Sabins Equivalent sound absorption area in metric sabins from surface area and absorption coefficient.
- Traffic Noise L10 Estimate Calculator Qualified caller-reference retrieval for Traffic Noise L10 Estimate Calculator. Independently applicable actual trafficflow/speed/heavyfraction/geometry/receiver/road and independentlyvalidatedtrafficL10calibration;no universalforecast. Does not compute omitted scientific/design/predictive models or publish authoritative complete tables. Source truth and applicability external;examples illustrative. No diagnosis,compliance,identity determination,safe-use approval or guaranteed forecast.
- Ultrasound Wavelength Tissue Ultrasound wavelength in millimetres from tissue sound speed and transducer frequency in megahertz.
- VC Vibration Curve Reference Return the meaning and selection cautions of vibration-criterion curves for sensitive facilities.
- Vern Knudsen History Return documented contributions of Vern Oliver Knudsen without assigning a disputed “first acoustician” title.
- Vibrating String Fundamental Ideal stretched-string fundamental frequency from length, tension, and mass per unit length.
- Wall Coincidence Frequency Calculator Idealcriticalcoincidencefrequencythinplate c²/(2π)√(m/D),not arbitrarySTC from masslaw. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.
- Wave Number Calculator Angular wave number in radians per metre from positive wavelength.
- Wavelength From Frequency Acoustic wavelength in metres from wave speed and positive frequency.
- Wenz Curve Reference Return the source-band interpretation and limitations of Wenz ocean-noise curves.
- Whale Vocalization Band Reference Return broad vocalization-band context without treating species as fixed-frequency signal generators.
- Whispering Gallery Reference Return the geometric-acoustics mechanism and limitations of whispering-gallery propagation.
- WHO Night-Noise Reference Return the WHO Europe night-noise guideline and interim-target context.
- Windscreen Insertion Loss Calculate measured windscreen insertion loss at a caller-specified frequency without generalizing it to other windscreens or incidence conditions.