CLICKABLE CONTENTS
Unless otherwise indicated, all the calculators, simulators,
converters etc here are free (though only as trial versions in a couple of cases). I have not tested all of them - any feedback is very welcome.
GENERAL
Ares acoustic modelling, measurement and design tools (McIntosh applied Engineering)
http://maellc.com/
"Compared with other FEA/BE tools, Ares provides faster prediction and provides users with good understanding of the underlying acoustics without the need to have a strong knowledge of lumped equivalent circuit design."
includes modules for
Acoustic Modeling
Flow Impedance Measurement
Frequency Response Measurement
Speaker Parameterization
Coordinate Mapper
NOTE: these modules are not free, but a trial version of the Acoustic Modeller is available.
Paul Falstad's applets for a wide range of mathematical, scientific and engineering-related topics
http://www.falstad.com/mathphysics.html
Includes
Ripple tank
2-D Waves
3-D Waves
Coupled oscillations
Dispersion and group velocity
Loaded string
Vibrational modes in a 2-d membrane
Vibrational modes in a 2-d circular membrane (drum head)
Bending waves in a bar
Vowels
Acoustic standing waves in a 3-d box
Loudspeaker interference
Fourier series
Digital filters
Huge range of calculators related to audio, electro acoustics and music (Sengpielaudio)
http://www.sengpielaudio.com/Calculations03.htm
Includes:
Absorption coefficients of building materials and finishes
Absorption of sound by the atmosphere
Active Audio-Filter calculation
Adding amplitudes and levels
Adding of incoherent sound sources
Air damping formulae (High frequencies / Dissipation) calculation
ALcons and STI speech − Intelligibility conversion
Amplification (gain) and damping (loss) in dB − Computation
Bandwidth in octaves to Q factor (filter) conversion
Bass reflections at walls
Beats per minute counter and calculator
Comb filters
Combine levels of one-third octave bands to octave band
Damping (decrease) of sound level with distance r (noise propagation)
Damping of bridging and damping factor calculation in audio
Decibel calculator (dB)
Decrease in level of sound pressure and sound intensity with distance
Delay time and Interference (ITDG)
Direct field (Free field) and Reverberant field (Diffuse field)
Equalization (EQ filter)
Extension angle of the orchestra calculation (microphone position)
Frequency domain of musical instruments, voices (vocals), and keyboards
Frequency ratio (interval) to cents conversion and vice versa
Harmonics and Overtones
Johnson noise
Localisation direction
Loudspeaker sensitivity to efficiency conversion
Microphone sensitivity conversion
Nepers to decibels conversion and vice versa
Pitch change by temperature change (variation) - wind instruments
Recording Angle
Reverb time RT60
Reverberation time RT60 to Sound decay rate conversion
Room modes − Axial, tangential, and oblique modes
Sones and phons loudness conversion
Sound field quantities of a plane wave
Speed of sound in air
SRA calculation of Δ L and Δ t for stereo microphone arrays
Standing waves in air
Standing waves on a string and room modes between parallel walls
Temperature dependence of acoustic quantities
Thermal noise
Total Harmonic Distortion
Voltage V to dBu, dBV, and dBm
Weighting filter (dBA and dBC)
White noise
Ares acoustic modelling, measurement and design tools (McIntosh applied Engineering)
http://maellc.com/
"Compared with other FEA/BE tools, Ares provides faster prediction and provides users with good understanding of the underlying acoustics without the need to have a strong knowledge of lumped equivalent circuit design."
includes modules for
Acoustic Modeling
Flow Impedance Measurement
Frequency Response Measurement
Speaker Parameterization
Coordinate Mapper
NOTE: these modules are not free, but a trial version of the Acoustic Modeller is available.
Paul Falstad's applets for a wide range of mathematical, scientific and engineering-related topics
http://www.falstad.com/mathphysics.html
Includes
Ripple tank
2-D Waves
3-D Waves
Coupled oscillations
Dispersion and group velocity
Loaded string
Vibrational modes in a 2-d membrane
Vibrational modes in a 2-d circular membrane (drum head)
Bending waves in a bar
Vowels
Acoustic standing waves in a 3-d box
Loudspeaker interference
Fourier series
Digital filters
Huge range of calculators related to audio, electro acoustics and music (Sengpielaudio)
http://www.sengpielaudio.com/Calculations03.htm
Includes:
Absorption coefficients of building materials and finishes
Absorption of sound by the atmosphere
Active Audio-Filter calculation
Adding amplitudes and levels
Adding of incoherent sound sources
Air damping formulae (High frequencies / Dissipation) calculation
ALcons and STI speech − Intelligibility conversion
Amplification (gain) and damping (loss) in dB − Computation
Bandwidth in octaves to Q factor (filter) conversion
Bass reflections at walls
Beats per minute counter and calculator
Comb filters
Combine levels of one-third octave bands to octave band
Damping (decrease) of sound level with distance r (noise propagation)
Damping of bridging and damping factor calculation in audio
Decibel calculator (dB)
Decrease in level of sound pressure and sound intensity with distance
Delay time and Interference (ITDG)
Direct field (Free field) and Reverberant field (Diffuse field)
Equalization (EQ filter)
Extension angle of the orchestra calculation (microphone position)
Frequency domain of musical instruments, voices (vocals), and keyboards
Frequency ratio (interval) to cents conversion and vice versa
Harmonics and Overtones
Johnson noise
Localisation direction
Loudspeaker sensitivity to efficiency conversion
Microphone sensitivity conversion
Nepers to decibels conversion and vice versa
Pitch change by temperature change (variation) - wind instruments
Recording Angle
Reverb time RT60
Reverberation time RT60 to Sound decay rate conversion
Room modes − Axial, tangential, and oblique modes
Sones and phons loudness conversion
Sound field quantities of a plane wave
Speed of sound in air
SRA calculation of Δ L and Δ t for stereo microphone arrays
Standing waves in air
Standing waves on a string and room modes between parallel walls
Temperature dependence of acoustic quantities
Thermal noise
Total Harmonic Distortion
Voltage V to dBu, dBV, and dBm
Weighting filter (dBA and dBC)
White noise
AUDIO / RECORDING
Acoustic toolBox app (acoustassist ltd)
https://play.google.com/store/apps/details?id=com.acoustassist.toolBox
includes
room acoustics
outdoor propagation
sound systems
Speedy spectrum analyser
http://speedy-spectrum-analyzer.soft112.com/
NB there is also a professional version of the spectrum analyser, available as an app by Electron Chaos, though it costs £3.99
https://play.google.com/store/apps/details?id=com.electronchaos.SpeedySpectrumAnalyzer&hl=en_GB
Audio spectrum analyser (Techmind.org)
http://www.techmind.org/audio/specanaly.html
Suite of audio-related calculators (Pro Audio) [NEW]
http://www.doctorproaudio.com/doctor/calculadores_en.htm
includes
SPL addition
Ceiling speaker coverage
Air Absorption
Q
Daniel Lurcock's mobile-optimised web-based calculator [NEW]
http://www.acoustassist.com/products.html
includes
A selection of audio test signals (plus, the downloadable app includes the option to download individual signals for offline use)
Unique decibel calculator
Room modes calculator
Octave/third-octave frequency bands calculator with A/B/C/D weightings
Noise rating (NR) level calculator
Reverberation time calculators (simple and advanced modes)
Suite of audio calculators (Hotto Engineering)
http://www.hotto.de/software.html
includes
Active Bass Trap
Quadrophonic Matrix Encoder
Audio Mastering Suite
Ambiophonic Audio Player
Ambiophonic Transcoder
Audio Compressor & Limiter
Frequency Response Correction
CIP Audio Player
LM Simulator
Dynamic Simulator
Audio Valve Simulator
Loudspeaker design and construction (HiFi Speaker Design)
http://www.mh-audio.nl/spk_calc.asp
Maximum and minimum sound levels for selectable microphone/recorder combinations (megalithia)
http://www.megalithia.com/elect/noisecalc.html
Microphone calculators (ClearOne)
http://www.clearone.com/mic_calc
includes calculators of
Potential Acoustic Gain and Needed Acoustic Gain for speech lift
Maximum distance that a microphone can be placed from a talker
Acoustic toolBox app (acoustassist ltd)
https://play.google.com/store/apps/details?id=com.acoustassist.toolBox
includes
room acoustics
outdoor propagation
sound systems
Speedy spectrum analyser
http://speedy-spectrum-analyzer.soft112.com/
NB there is also a professional version of the spectrum analyser, available as an app by Electron Chaos, though it costs £3.99
https://play.google.com/store/apps/details?id=com.electronchaos.SpeedySpectrumAnalyzer&hl=en_GB
Audio spectrum analyser (Techmind.org)
http://www.techmind.org/audio/specanaly.html
Suite of audio-related calculators (Pro Audio) [NEW]
http://www.doctorproaudio.com/doctor/calculadores_en.htm
includes
SPL addition
Ceiling speaker coverage
Air Absorption
Q
Daniel Lurcock's mobile-optimised web-based calculator [NEW]
http://www.acoustassist.com/products.html
includes
A selection of audio test signals (plus, the downloadable app includes the option to download individual signals for offline use)
Unique decibel calculator
Room modes calculator
Octave/third-octave frequency bands calculator with A/B/C/D weightings
Noise rating (NR) level calculator
Reverberation time calculators (simple and advanced modes)
Suite of audio calculators (Hotto Engineering)
http://www.hotto.de/software.html
includes
Active Bass Trap
Quadrophonic Matrix Encoder
Audio Mastering Suite
Ambiophonic Audio Player
Ambiophonic Transcoder
Audio Compressor & Limiter
Frequency Response Correction
CIP Audio Player
LM Simulator
Dynamic Simulator
Audio Valve Simulator
Loudspeaker design and construction (HiFi Speaker Design)
http://www.mh-audio.nl/spk_calc.asp
Maximum and minimum sound levels for selectable microphone/recorder combinations (megalithia)
http://www.megalithia.com/elect/noisecalc.html
Microphone calculators (ClearOne)
http://www.clearone.com/mic_calc
includes calculators of
Potential Acoustic Gain and Needed Acoustic Gain for speech lift
Maximum distance that a microphone can be placed from a talker
AUDIOMETRY / HEARING / SPEECH
Auditory Brainstem Response masking noise calculator (National Health Service)
http://hearing.screening.nhs.uk/audiology
http://hearing.screening.nhs.uk/getdata.php?id=23833
Hearing loss simulator
http://www.hearinglikeme.com/facts/what-hearing-loss/hearing-loss-simulator-understanding-mild-and-moderate-hearing-loss
Speech recording, display and analysis (University College London)
http://www.phon.ucl.ac.uk/resource/sfs/wasp.htm
Auditory Brainstem Response masking noise calculator (National Health Service)
http://hearing.screening.nhs.uk/audiology
http://hearing.screening.nhs.uk/getdata.php?id=23833
Hearing loss simulator
http://www.hearinglikeme.com/facts/what-hearing-loss/hearing-loss-simulator-understanding-mild-and-moderate-hearing-loss
Speech recording, display and analysis (University College London)
http://www.phon.ucl.ac.uk/resource/sfs/wasp.htm
MUSIC / SOUND ART
Audio tool
Music-making package
http://www.audiotool.com/
Database of c. 1000 leisure events/activities (Australian Government Department of Health & National Acoustic Laboratories)
noisedb.nal.gov.au
Sound effects library (AudioMicro)
http://www.audiomicro.com/free-sound-effects/free-musical-instrument-and-sound-effects
Synthesiser (Nick's World of Synthesizers)
http://nicksworldofsynthesizers.com/flashbeast.php
Audio tool
Music-making package
http://www.audiotool.com/
Database of c. 1000 leisure events/activities (Australian Government Department of Health & National Acoustic Laboratories)
noisedb.nal.gov.au
Sound effects library (AudioMicro)
http://www.audiomicro.com/free-sound-effects/free-musical-instrument-and-sound-effects
Synthesiser (Nick's World of Synthesizers)
http://nicksworldofsynthesizers.com/flashbeast.php
NOISE
Suite of software related to indoor and outdoor noise (Sheffield University Acoustics Group)
http://acoustics.group.shef.ac.uk/asaproject.php
includes
Sound reduction behind an environmental noise barrier
Sound distribution and reverberation in street canyons
Absorption coefficient of micro-perforated absorbers
Reverberation time in a rectangular space
Digital audio animation for the soundscape design of urban streets and squares
Insulation, absorption and propagation (dB waves)
http://www.dbwaves.com
Noise barriers (MAS Environmental)
http://www.masenv.co.uk/noisecalculator2
Required sound insulation for buildings (Azymuth)
http://www.azymuth.co.uk/wp/calculator/
Reverberation time calculator (SAE Institute)
http://www.sae.edu/reference_material/pages/Reverberation%20Time%20Calculator.htm
Total noise (U.S. Department of Housing and Urban Development)
http://portal.hud.gov/hudportal/HUD?src=/program_offices/comm_planning/environment/dnlcalculatortool
Includes road and rail noise
Total noise from three sources (MAS Environmental)
http://www.masenv.co.uk/noisecalculator
Total noise from four sources (Spirex Sarco)
http://www.snapfour.com/combinednoise_calculations.aspx
Traffic noise generator (mynoise.net)
http://mynoise.net/NoiseMachines/trafficNoiseGenerator.php
Ara Sargsyan's Weighted Sound Reduction Index (Rw) / Sound Transmission Class (STC) Calculator
http://www.ara4help.com/Green.html
"This calculator determines Rw and STC values of monolithic materials (e.g. concrete, glass, steel) using graphical computation method based on the material thickness, density, and critical frequency values. The computation logic is based on both US and European methodologies and results of actual Test Room measurements."
Wind turbine noise (National Physical Laboratory Acoustics Group)
http://resource.npl.co.uk/acoustics/techguides/wtnm/
Noise assessments (Noisemeters Ltd UK)
https://www.noisemeters.co.uk/apps/
includes
Decibels
Ldn and Lden
Noise exposure
LEP,d, LEPw noise exposures
Sound level at ear while wearing hearing protectors
Sound map calculator for wind farm noise (Danish Wind Industry Association)
http://www.motiva.fi/myllarin_tuulivoima/windpower%20web/en/tour/env/db/dbcalc.htm
Noise exposure (Health and Safety Executive)
www.hse.gov.uk/noise/calculator.htm
Room Acoustics Calculator (Hunecke.de)
http://www.hunecke.de/en/calculators/room-acoustics.html
"The Room Acoustics Calculator enables you to design the acoustics of a room according to DIN 18041 and ÖNORM B 8115-3. After the usage and the appropriate standard have been selected the calculator derives the relevant design quantities, tolerance ranges or limits, and the corresponding state of the room (furnished, unfurnished, occupied or unoccupied)."
Noise propagation (MAS Environmental)
www.masenv.co.uk/noisecalculator
Noise exposure risk calculator & speech in noise test (Australian Government Department of Health & National Acoustic Laboratories)
knowyournoise.nal.gov.au
Suite of software related to indoor and outdoor noise (Sheffield University Acoustics Group)
http://acoustics.group.shef.ac.uk/asaproject.php
includes
Sound reduction behind an environmental noise barrier
Sound distribution and reverberation in street canyons
Absorption coefficient of micro-perforated absorbers
Reverberation time in a rectangular space
Digital audio animation for the soundscape design of urban streets and squares
Insulation, absorption and propagation (dB waves)
http://www.dbwaves.com
Noise barriers (MAS Environmental)
http://www.masenv.co.uk/noisecalculator2
Required sound insulation for buildings (Azymuth)
http://www.azymuth.co.uk/wp/calculator/
Reverberation time calculator (SAE Institute)
http://www.sae.edu/reference_material/pages/Reverberation%20Time%20Calculator.htm
Total noise (U.S. Department of Housing and Urban Development)
http://portal.hud.gov/hudportal/HUD?src=/program_offices/comm_planning/environment/dnlcalculatortool
Includes road and rail noise
Total noise from three sources (MAS Environmental)
http://www.masenv.co.uk/noisecalculator
Total noise from four sources (Spirex Sarco)
http://www.snapfour.com/combinednoise_calculations.aspx
Traffic noise generator (mynoise.net)
http://mynoise.net/NoiseMachines/trafficNoiseGenerator.php
Ara Sargsyan's Weighted Sound Reduction Index (Rw) / Sound Transmission Class (STC) Calculator
http://www.ara4help.com/Green.html
"This calculator determines Rw and STC values of monolithic materials (e.g. concrete, glass, steel) using graphical computation method based on the material thickness, density, and critical frequency values. The computation logic is based on both US and European methodologies and results of actual Test Room measurements."
Wind turbine noise (National Physical Laboratory Acoustics Group)
http://resource.npl.co.uk/acoustics/techguides/wtnm/
Noise assessments (Noisemeters Ltd UK)
https://www.noisemeters.co.uk/apps/
includes
Decibels
Ldn and Lden
Noise exposure
LEP,d, LEPw noise exposures
Sound level at ear while wearing hearing protectors
Sound map calculator for wind farm noise (Danish Wind Industry Association)
http://www.motiva.fi/myllarin_tuulivoima/windpower%20web/en/tour/env/db/dbcalc.htm
Noise exposure (Health and Safety Executive)
www.hse.gov.uk/noise/calculator.htm
Room Acoustics Calculator (Hunecke.de)
http://www.hunecke.de/en/calculators/room-acoustics.html
"The Room Acoustics Calculator enables you to design the acoustics of a room according to DIN 18041 and ÖNORM B 8115-3. After the usage and the appropriate standard have been selected the calculator derives the relevant design quantities, tolerance ranges or limits, and the corresponding state of the room (furnished, unfurnished, occupied or unoccupied)."
Noise propagation (MAS Environmental)
www.masenv.co.uk/noisecalculator
Noise exposure risk calculator & speech in noise test (Australian Government Department of Health & National Acoustic Laboratories)
knowyournoise.nal.gov.au
ULTRASONICS
Ultrasonic formulae, with links to calculators of Near Field and Beam Divergence (NDT Resource Centre)
https://www.nde-ed.org/GeneralResources/Formula/UTFormula/ultrasonicFormula.htm
Suite of converters between acoustic units, including SPL to pressure & intensity, decibels to pascals & watts per square metre (Sengpielaudio)
http://www.sengpielaudio.com/calculator-soundlevel.htm
Hydrophone electrical loading (National Physical Laboratory)
http://resource.npl.co.uk/acoustics/techguides/loading/loadcalc1.html
Ultrasonics calculators (NDTCalc.com)
http://www.ndtcalc.com/calculators.html
includes
Snells Law
Beam Spread
Near Zone
Time of flight
Ultrasonics calculators (NDT Resource Center)
https://www.nde-ed.org/GeneralResources/Calculator/calculator.htm
includes
Acoustic Impedance
Beam Spread
Field Zone
Reflection and Transmission Coefficients
Snell's Law
Ultrasonic Measurement of Texture
Ultrasonic formulae, with links to calculators of Near Field and Beam Divergence (NDT Resource Centre)
https://www.nde-ed.org/GeneralResources/Formula/UTFormula/ultrasonicFormula.htm
Suite of converters between acoustic units, including SPL to pressure & intensity, decibels to pascals & watts per square metre (Sengpielaudio)
http://www.sengpielaudio.com/calculator-soundlevel.htm
Hydrophone electrical loading (National Physical Laboratory)
http://resource.npl.co.uk/acoustics/techguides/loading/loadcalc1.html
Ultrasonics calculators (NDTCalc.com)
http://www.ndtcalc.com/calculators.html
includes
Snells Law
Beam Spread
Near Zone
Time of flight
Ultrasonics calculators (NDT Resource Center)
https://www.nde-ed.org/GeneralResources/Calculator/calculator.htm
includes
Acoustic Impedance
Beam Spread
Field Zone
Reflection and Transmission Coefficients
Snell's Law
Ultrasonic Measurement of Texture
UNDERWATER ACOUSTICS
Suite of underwater acoustics calculators (U.S. Office of Naval Research)
http://oalib.hlsresearch.com/Rays/
Includes
Ray tracing
Normal Modes
Parabolic Equation
Wavenumber integration
Speed of sound in seawater (National Physical Laboratory)
http://resource.npl.co.uk/acoustics/techguides/soundseawater/content.html
Underwater sound levels (peak, RMS, sound exposure) (NMFS)
NMFS Calculator
Hydrophone electrical loading (National Physical Laboratory)
http://resource.npl.co.uk/acoustics/techguides/loading/loadcalc1.html
Sonar beam angle (Furuno USA)
http://www.furunousa.com/LearningCenter/Transducer-Beam-Angle-Calculator.aspx
Sonar (demonstration version) (Echoview)
http://support.echoview.com/WebHelp/Reference/Algorithms/Sonar_calculator_algorithms.htm
(equations and links)
http://support.echoview.com/WebHelp/Windows_and_Dialog_Boxes/Dialog_Boxes/About_Sonar_Calculator.htm
(introduction)
Suite of underwater acoustics calculators (U.S. Office of Naval Research)
http://oalib.hlsresearch.com/Rays/
Includes
Ray tracing
Normal Modes
Parabolic Equation
Wavenumber integration
Speed of sound in seawater (National Physical Laboratory)
http://resource.npl.co.uk/acoustics/techguides/soundseawater/content.html
Underwater sound levels (peak, RMS, sound exposure) (NMFS)
NMFS Calculator
Hydrophone electrical loading (National Physical Laboratory)
http://resource.npl.co.uk/acoustics/techguides/loading/loadcalc1.html
Sonar beam angle (Furuno USA)
http://www.furunousa.com/LearningCenter/Transducer-Beam-Angle-Calculator.aspx
Sonar (demonstration version) (Echoview)
http://support.echoview.com/WebHelp/Reference/Algorithms/Sonar_calculator_algorithms.htm
(equations and links)
http://support.echoview.com/WebHelp/Windows_and_Dialog_Boxes/Dialog_Boxes/About_Sonar_Calculator.htm
(introduction)
VIBRATION
Vibration exposure limit (Makita UK)
http://www.makitauk.com/vibration_calculator.asp
Suite of vibration calculators (Mobius Institute)
http://www.mobiusinstitute.com/site2/detail.asp?LinkID=54
includes
Bearing defect frequencies
Fmax from shaft rotation
Gear Assembly Phase Frequencies [GAPF]
Hunting Tooth Frequency [HTF]
A.C. induction motor vibration characteristics
Vibration from pumps and fans
Vibration units conversion
ISO 10816 Displacement - interactive vibration severity chart, vibration alarm limits, acceptable vibration limits.
Alarm limits for common machines
Signal generator
Variable excitation frequency mass and spring
Hand/arm vibration (Health and Safety Executive)
www.hse.gov.uk/vibration/hav/vibrationcalc.htm
Workplace exposure calculator
Vibration exposure limit (Makita UK)
http://www.makitauk.com/vibration_calculator.asp
Suite of vibration calculators (Mobius Institute)
http://www.mobiusinstitute.com/site2/detail.asp?LinkID=54
includes
Bearing defect frequencies
Fmax from shaft rotation
Gear Assembly Phase Frequencies [GAPF]
Hunting Tooth Frequency [HTF]
A.C. induction motor vibration characteristics
Vibration from pumps and fans
Vibration units conversion
ISO 10816 Displacement - interactive vibration severity chart, vibration alarm limits, acceptable vibration limits.
Alarm limits for common machines
Signal generator
Variable excitation frequency mass and spring
Hand/arm vibration (Health and Safety Executive)
www.hse.gov.uk/vibration/hav/vibrationcalc.htm
Workplace exposure calculator
OTHER
Acoustic impedance (NDT Resource Centre)
https://www.nde-ed.org/EducationResources/CommunityCollege/Ultrasonics/Physics/acousticimpedance.htm
Acousto-optic effect (OpticalCalculation.com)
http://www.optical-calculation.com/tutorials/acousto_optic.php?PHPSESSID=0bcc01b7386d34631d41c5208609cb33
Fourier analysis (Maths Tools)
http://www.mathstools.com/section/main/On_Line_Fourier_Series#.VJAaGHuCErU
Ripple tank simulator (e.chalk)
http://www.echalk.co.uk/Science/Physics/rippleTank/ripple.htm
Sound radiation and scattering simulator (BEM acoustics)
http://www.bemacoustics.com/
Speed of Sound (EngineeringToolBox.com)
www.engineeringtoolbox.com/speed-sound-d_519.html