Questions related to Acoustic Analysis
I'm studying the effectiveness of ultrasound as a wolf deterrent. A first step in this, is measuring how loud the speakers that we use actually are. Decibel meters which operate in the ultrasound range are very expensive, and DIY solutions don't always seem very accurate. The solutions we are left with are either a) build our own decibelmeter and calibrator or b) find a lab (in Germany) where these types of tests are being done, so we can bring our own equipment there to test it.
We would only need to test the speakers a limited number of times, so we were thinking that building our own device might require too much time and resources.
Does anyone have any suggestions or possible solutions?
Thank you very much!
Can anyone recommend a usable resource/tool for species detection from acoustic data please? A middle ground between a phone app and something like Arbimon would be about the level. Briefly, a phone app lacks flexibility in data collection, i.e. it cant be left out all night or left running for long periods. However, Arbimon is not that useful to anyone below ecologist level, as it only tells the user what species is present if the user completes their own validation, i.e. the user has to identify all species themselves. I'm looking for something that can analyse data from an AudioMoth, uploaded by citizen scientist participants, and actually identify species.
Is there any relationship between stl and absorption coefficient?
Suppose i am getting a peak at 400Hz (90% absorption) then at the same frequency what will be the sound transmission loss(it will be minimum or maximum or we can not say).
Please see attachment, here two terms appeared in the inhomogeneous Helmholtz equation. What is the use of these two terms for a propagating wave in a particular direction.
I am looking for links of audio datasets that can be used in classification tasks in machine learning. Preferably the datasets have been exposed in scientific journals.
Thank you for your attention and valuable support.
Hi everyone, I have a query regarding the elbow and its insertion loss captured in ASHRAE.
The elbow captured in the ASHRAE is referring to what kind dimension? I have attached three common scenarios which I have quite often encounter during FCU noise control design stage.
Looking for advise.
I am searching for good recordings of distress calls emitted by American crocodiles, in particular by hatchlings. The longer the better. If not, also distress call recordings of other crocodilian species are fine.
i am working on in which i has to trace band limited noise using Bellhop matlab but i am new in matlab and also not much familiar with acoustics can anyone please help me it's urgent..
I'm a spatial planning master student, I'm studying the soundscape in Jordan- Amman, the methodology I will use is varied from a questionnaire (Soundwalk) to a binaural recording, and I'm wondering if you have any recommendation for questions to be asked in the Soundwalk?
I am an undergraduate working on modelling generator noise through an aperture and writing my literature review has been a little extra difficult.
I have been trying to understand the methods of noise analysis in acoustic engineering. There are four of them which are mostly used. And I need to understand each of them to be able to choose the method I would be using in my modelling.
If you have any material, book or journal that could assist me with my research work please do send in, would be very much appreciated.
I am trying to account for amplitude damping of acoustic vibration of a polymer disc, using Ansys software. I am currently using Harmonic Acoustics module in Ansys, which seems to be the only one allowing FSI boundary between the surrounding acoustic medium (water) and the structure (polymer disc).
I recently asked Ansys support, and turns out the effect of damping on amplitude of vibration cannot be modeled with it: https://forum.ansys.com/discussion/comment/125750#Comment_125750
Now my question is, is there any way to work around this issue by changing the mechanical properties of the polymer in my mode, to account for viscous damping of water? Like probably to calculate some kind of equivalent damping to assign to polymer material in my model instead?
Thanks in advance for your help.
Hello, may I know how to compute the overall sound absorption coefficient of 2 or more items together (coefficient for overall system)?
1. item 34 on the surface of item 28?
2. item 12 on the surface of item 38?
Kindly refer to the attachment to get the item.
such as Fourier , Hilbert or Laplace transforms in order to analysis and studies in the field of music acoustics.
I am trying to find acoustic round-trip latency of Android smartphones. I have using the technique of where I play a beep and listen to it through the phone and then perform convolution and get time index where we get the peak value.
Here the issue is that when we play our beep, the AEC and NS of Android smartphones cancel and attenuate the beep and it cant be seen in recorded data.
Background & Relevant Information:
Most of the applications that measure acoustic latency such as the OboeTester app etc. use VOICE_RECOGNITION (https://developer.android.com/reference/android/media/MediaRecorder.AudioSource#VOICE_RECOGNITION) mode. In this mode, no DSP is performed and we get raw data. But this excludes the latency of DSP algorithms performed by the built-in components.
What I want:
I want to find the round trip latency using VOICE_COMMUNICATION mode. In this mode, all components of AEC, AGC, and NS are activated. But this cancels our beep and we can't get accurate results.
Is there any want to find latency while AEC and NS are working. Looking forward for the solution.
Whether Acoustic Vibrations can be used to damage / fracture the CORONA VIRUS (COVID-19) structure ?
Acoustics with resonance frequency of the COVID-19 can be used to prevent this Pandemic ?
Please see the attachment.
1- I have to use Perfectly matched layer while using port boundary condition or not.
2- My port shape is hexagonal.
So from available options, I am choosing user defined port. But while computation it is showing error.
I am pondering whether or not the vibrato traditionally present in Western classical singing (Bel Canto) bears any significant influence on perturbation or noise measures – vibrato has been defined as variance in frequency and amplitude, as well as having aerodynamic interaction with vocal-fold vibration/oscillation. I am unsure if clinical measures such as VTI, HNR, RAP, etc will be confounded by its presence in sung voice samples. The majority of literature I've looked at supports CPP(S) as one of the most robust acoustic voice measurements across a wide variety of tasks, but I am wanting to include other measures in my analysis of singing students too. Any insight or ideas? Thank you.
I have modelled a unit-cell of an anechoic structure using ANSYS. The layer is silicone and has been assigned as an acoustics physics region, with an air cavity inside (the air has been modelled and also assigned as an acoustics physics region). There is a steel backplate as well that is structural. In order to simulate the water closure on the silicone layer face I have applied an impedance boundary condition, assigned a port to this front surface and used the body of the same layer to assign the inside surface bodies. A planar wave has been applied using a 'port in duct' excitation condition (with 10000 Pa) and the acoustic absorbance is calculated.
I have used the same material parameters that I have seen in many papers, however I am getting very different results and wondered if anybody could please highlight where I have modelled it incorrectly or explain the observed behaviour? I have included an image of the absorption coefficient with regards to frequency in a 0-6000 kHz range.
Thank you for any help.
I am a final year university student and for my honours project I am studying the effects of the size of air-filled cavities in an anechoic layer. The layer is made of silicone and has a steel plate backing. It is surrounded by a water enclosure, the surfaces in the x and y planes of the anechoic layer have a frictionless support applied to them to stop displacement in the normal directions. I am however having trouble with the remainder of the boundary conditions, namely the mesh sizing and whether I have to use commands to apply specific nodal values (using FLUID 30?).
Any help would be greatly appreciated. Thank you.
Good afternoon everyone,
I'm planning on studying and comparing the amount of underwater "noise" in different areas, and later, potentially, linked it with marine mammals occupancy. However I was wondering, what is the most suitable way to do it? Would it be by doing transects and dragging a hydrophone behind a sailing boat, or by submerging a few at different locations? What would be the advantages or disadvantages of both methods?
We would like to sample these oceanic sounds at three different times as well.
Thank you in advance!
I did an experiment on a glass composite thin plate and generated Lamb wave. I increased the stiffness of the plate by forming a sandwich structure. I could find Ao mode with very attenuated amplitude but So is very diminishing. Confused, as per my understanding, I should get both modes frequencies even if the amplitude is small. But only Ao I could obtain its frequency but So not.
I'm in the process of buying new equipment to record the vocalizations of wild mammals, and have used Marantz's solid state recorders with great success in the past. However, it seems that their PMD range of recorders are not easily available anymore. I've looked around and the Tascam DR-1 portable solid state recorder seems like a good option, but I have no experience with that product.
I'd appreciate any advice on the best, portable recorders to be used in the field. Nothing too fancy (I don't expect ultrasonic vocalizations, for example), but I'd love to hear from you about the pro's and cons of different recording tools that you've used. I would need the recordings to be of good enough quality to analyze properly in programs like AviSoft.
When some of the call properties show negative correlation with temperature . Is it necessary to perform temperature correction of such properties ? What are the steps involved in the correction.
Platz and forester, 1988 gives the formula D14 = Damb - (Tamb. -14.0) (-0.0974) . Can we apply our desired temperature here (Eg. 20 °C ? Or is there any better way to perform this correction
I'm curious to know if one can find the force of the collision by analyzing the audio or extracting features from the audio signal that estimates the force.
I'm looking for any kind of legislation, zoning, best practices, etc. either required or recommended by the state, the EU/other federation or local government.
While working on squirrel calls, I found that the frequency of the sound produced by individuals from mean sea level is quite more than the same from an elevation of about 2000 metres. Does the frequency depends upon the elevation of habitat and changes with change in the height or their is something else behind the aforesaid phenomenon.
Anyone have any idea on how to harvest the acoustic energy from a line sound source? The line sound source is in small scale, maybe in a centimeter range, and the sound pressure is very small, around uPa I guess.
some metal surfaces, rubbed against each other squeaks in a shrilling high frequency. Why? What is the role of surface roughness, friction factor, geometric shape, stress distribution,solid and medium sound velocity, strength, resilience and microstructure to frequency spectrum of the sound? Are there any set of differential equations that describe this phenomena? How to construct a model concerning the phenomena?
Suppose avg. grain size, crystal structure, young's Modulus, fracture strength, velocity of sound and surface roughness of both the crushed crystals (before and after crushing ) and the crushing surfaces, as well as load on grinding surface, static/dynamic friction coefficients are known. Then, is it possible to estimate the crushing sound of the crystals?
Conversely, if crushing sound of the crystals are analyzed, is it possible to find any mathematical relation between the variables outlined?
I am asking the questions since crushing minerals and recording-analyzing the sound require no sophisticated instrument at all.
Please provide relevant research links.
I am using FFT(Matlab) to convert time domain curve in frequency domain but it is showing me the number of samples in X-axis instead of frequency. How to obtain the frequency in X axis in frequency domain curve obtained from time domain using FFT?
Hi, I built a 2D plain strain model, put a concentrated time-harmonic force below the free surface, and detected Rayleigh wave on the free surface, I found that the amplitude of Rayleigh wave decay with the distances increasing. The material is aluminum, I just set density, Young modulus, no damping. I have no idea why the amplitude of Rayleigh wave would decay with distance.
Hi I need to model PA system for a train station with EASE.
I got this doubt, while a speaker makes announcement, sound from it have all frequencies or it will be at one particular frequency.
Because in EASE, it divides electric power equally among all frequencies.
If there are 21 frequencies, and electric power provided is 0.75W, then for each frequency the power is (0.75/21). We use pink noise.
Since the power gets distrbuted we are not getting the desired SPL.
Sound Power Level of a speaker is computed from the sound power of the speaker.
Sound power from the speaker is the total sound energy emitted by a speaker per unit time.
How this sound power is related to the electric power given to the speaker. For example if I give 6W electric power to the speaker then sound power from the speaker will be only 6W.
I have difference frequency iterations and pressure values for each iteration. I want a single final frequency-pressure curve. How to convert all the frequency-pressure curve to single resultant frequency-pressure curve?
What is the minimum computer specification required for the following simulations?
Suppose the following simulations should be apply for Lundell Alternator (with around 80 parts assembled on each other) and Starter Motor (With around 100 parts)
- Air flow simulation
- Dynamic Analysis
- Acoustic Analysis
- Static Analysis
- Fatigue Analysis
I should mention that the geometry of the parts in some cases are too complicated.
Thank you for giving me your time in advance.
I need to analyse the mean fundamental frequency of disordered voices and I found errors using the standard advanced settings of Praat autocorrelation procedure.
I found different articles which suggest to modify pitch floor and pitch ceiling but I cannot use a narrow pitch range because I am measuring the pitch range of dysphonic men and women.
Are you aware of guidelines on specific advanced settings (silence and voicing threshold, octave cost, octave-jump cost, voiced/unvoiced cost) for the alaysis of dysphonic voices?
Thank you for your help!
Valentina Di Natale
I would like to measure STI (speech transmission index) in a 3D environment. I have been thinking about use Unity and reproduce the sound from a speaker and record the sound from the character ears but I would like to find something more profesional. All has to be in 3D because the building is not real any more.
Thank you for your time.
I'm currently using Random Forests to classify acoustic data to corresponding bat species, however I was wondering if there is a way to also incorporate unsupervised cluster analysis into my classifier (such as K-Means or Hierarchical modelling)?
Whilst I have training data for ~40% of my target species, there is likely to be a large proportion of my field dataset which corresponds to species that haven't yet been described in the supervised model and therefore I would like for the classifier to be able to assign new clusters/call types to new classes (that hopefully can be matched to a species later).
I have been looking at consensus maximisation algorithms but I'm not sure if this would be the best method.
Any help is greatly appreciated!
(I'm not a computer scientist so please forgive me if this is a very straightforward question)
I am currently working on anthropogenic effects on the vocalisation of howler monkeys in the urban environment.
I record the vocalisations with a TASCAM DR-07MKii and I want to extract acoustic measurement such as frequency, pitch, rates and lengths of vocalisations.
Which program is easiest to use for a beginner to extract these variables?
I currently have: Sound Analysis Pro, Praat and Audacity.
All tips and additional information are very welcome
We have multiple arrays of microphones, each array well seperated from others on the ground. Our task is to track an aircraft that happens to pass by. But the terrain is such that there is a lot of reverberation. Now:
1) What prefiltering technique is best to remove reverberation effects.
2) Which weightings during GCC(Generalised Cross Correlation) are best against reverberation, while at the same time without increasing error by much.
Thank you very much.
Massachusetts Institute of Technology
I want to classify the reason for baby cry - unconformable, hungry, feeling Hot or cold etc by listing acoustical analysis of the audio signal.
Many applications in numerical acoustics occur in exterior domains. The advantage of benchmark problems is a closed form solution (e.g. circumferentially harmonic radiation from an infinite cylinder or radiation from a portion of the infinite cylinder). Different models such as perfectly matched layers (PML) and absorbing boundary conditions ABCs (like Enquist Majda, Bayliss Turkel) are used in the finite element method to approximate Sommerfelds radiation condition. I am interested in a publication, where these approaches are compared.
WHO ARE WE
Master Acoustics International Corp.was founded in Taiwan in 2017 by our Chief Director Mr. Jack Chen, who has a brilliant sense of both sound and frequency. Jack has used sound techniques to invent two of our innovative products: the sound optimized resonator and a sound optimized coating which can be painted on the surface of instruments. Both of these innovations dramatically improve the timbre of the instrument to which they are applied. The sound optimized resonator has already been patented in China with patent applications in process in Taiwan and Europe.
WHAT WE WANT TO DO – A draft blueprint for the project.
We conceived of this project and would propose three goals:
1. To examine our inventions to assess their effectiveness
2. To use collaboration to create new ideas/innovations/inventions
3. To formally present the project findings for everyone to see
LOOKING FOR PARTNERS
If you are interested in knowing more about Master Acoustics International and this project, or you can recommend any institutes or researchers. Please let us know, thanks!
I want to compare “neutral” baseline data with data recorded in a test session to finally be able to evaluate arousal/affect of the infant.
Which software would you recommend? Do you have any literature advice?
Any advice would be appreciated!
All the best
When obtaining sound absorption coefficient of Kenaf (Hibiscus Cannabinus- natural fiber) mix with latex rubber, results show that a drop performance at mid range frequency. Refer to the graph, Black line is sample with pure fiber contain. Blue dotted are Kenaf mix with latex rubber. Any strong evidence or reason behind the slop drop after 1000Hz for latex mixed sample and 2k Hz - 3k Hz for pure fiber sample? Reference journal / paper could be great if attach together.
Sound absorption coefficient obtain by using Impedance Tube Model SCS9020B Kundt/T60.
I am writing my MSc thesis about vocal communication in woolly monkeys and I want to make a general description of their different types of calls. I want to obtain various acoustic parameters such as duration, frequency range, low frequency, high frequency, maximum amplitude, average frequency, initial frequency, and final frequency. Hence, I have to analyse my recordings using SoundRuler, but I've never used this software before. I've read the instructions but I have some questions anyway.
- I recorded in stereo, so when I introduce the recording in the software, it asks me if I want to analyse left or right channel. Can I analyse both separately and then calculate the mean of both channels?
- Also, when I introduce the recording, I mark the section that I want to analyse using green bars. Once this section is marked, I proceed to do the analysis. Is it as easy as clicking the "manual" button? When I do it, it appears a table with the different values of the parameters, but I don't know if it is as "simple" as that.
That's all at the moment. Thank you for your answers!
Given that the data points are approx. 100,000, Fast Fourier Transform in Excel or other software does not support more than 4096 data points. Specific software or technique will be appreciated.
For the forensic evidence analysis of speech samples, the speaker specific phonetic and other linguistic parameters of acoustic signals are to be measued to compute the likelyhood ratio.
In what way SNR of an acoustic source can be measured in real time? Theoretically, we know that SNR=Psignal/Pnoise, but how we can put this into practice, i.e. how to implement it on an embedded controller?
I have decided to do research on noise pollution modeling. Kindly tell me open source software for noise pollution modeling around airport.
I used intependent component analysis to sepereate speech from noise.i used 2 microphones and two sources (speech and noise) . I got improvement in SNR when I used ICA but when I used ICA in speaker verification . I got bad performance compared with noisy test signal. Does any one used ICA to remove noise and used the enhanced speech after ICA in speaker verification?
I mean if we would want to modify a muffler based on parametric design, which parameters should be evaluated in the study, for example the cross section of the tube, the number of mufflers (inline or parallel), etc.
What kind of engine specifications should be evaluated in the study?
I have two acoustic signals (amplitude as a function of time). I do an FFT or Welch analysis to see, for which frequencies the two spectra are similar and where they differ. I am thinking of a correlation coefficient as a function of frequency. How do I do this (e.g. in matlab)?
PS the spectra are quite noisy.
In the past few years I been involved in sound analysis and condition monitoring of the car engine where the misfiring engine operating in workshop environment is successfully identified. I was also involved in research on Music Information Retrieval (MIR) where the system is provided with a sample record or part of a record and the system looks for similar records or records with similar queried part within them, based on their similarity and not their genre or style.
I am looking for a data set to apply my previous experiences in sound analysis on animal identification and even in the field of animal psychology.
This will be a inter/multi disciplinary work and scientific inputs are welcomed.
I want to make a speaker segmentation of the train base in TIMIT database.
I need the speaker labels to make evaluation with test label which i have done.
so Howcan do the speaker labeling on train data on TIMIT database?
Note: Speaker labels found in test are in TEXT Grid format.
Waitting your response...!! Thank you in advance!!!
Is there a "sound density limit" beyond which sound energy fails to be recorded and/or played back?
Example: one of the largest known choirs consisted of 121,440 people - if I wanted to record such an event (or as many overdubs as those or many more), would there be a density limit I would reach and if yes, how can it be calculated ?
What about natural events ? Imagine hailstroms for example. What would happen if I recorded many and created a sound file with dozens, even hundreds of those and played them back ? Would I be reaching any playback (or hearing) limits ? Would such density create some sort of coloured noise ?
All your ideas, suggestions and explorations will be very welcome
I want to give some reasonable explanation of my calculated results on the zeroth-order acoustical Bessel beam scattering from the forward half-space for rigid spheroids and finite cylinders. There is an obvious difference between the ordinary plane waves and Bessel beams. Could you suggest some appropriate physical models which may help to describe the results? Thank you very much.
I am trying to use ABAQUS for FEM analysis and LMS VirtualLab for BEM for an acoustic analysis. But there is not much documentation available on how to use them together for. Where do can I find the necessary tutorials?
on acoustic emission reaearch ,many authors used the formation on amplitude distibution model .n(a)=(a/a0)-b.and i want to know how to obtain b value?,i need you can list the example .who can help me ?
Dear Physicists, please I would like to know if there is a relation between the intensity of a signal acoustic wave and the ability of that wave signal to shatter a body. For instance, if a tuning fork is emitting an acoustic wave into body X (such as a glass cup) at a resonant frequency of body X (for instance the fundamental frequency) is there a threshold intensity (e.g. wave amplitude, wave power) of the wave emitted by the tuning fork which needs to be exceeded before body X will shatter? It seems well known that the shattering effect will occur at specific frequencies (the fundamental frequency or its harmonics) however, does the wave amplitude, power or other material properties of the body play a part? If yes, please what relation or formula governs these? Answers appreciated. Thanks
We want to study noise in scaled down room to utilize better noise control. We can use dimensionless analysis however it's better to stick to standards.
In doing acoustic analysis of a certain segmental or supra-segmental feature of a language, a researcher usually decides on the age range of speakers to be recorded and analyzed. This age range should represent a "generation". What is the most appropriate age range that better represents the current status of the intended feature in the language under analysis?
Some studies record males or females only, while some studies record both and report certain variations based on gender difference. The question is, is it essential to have both sexes recorded even if the researcher is not interested in gender variation?
Ecoacoustics has become a tool to assess biodiversity of calling animals using Passive Acoustic Monitoring (PAM) of soundscapes (for examples, search for the respective keywords https://www.researchgate.net/search.Search.html?type=publication&query=ecoacoustics&tabViewId=57865c2140485491311aff27&previous=researcher). Several projects host accessible recordings, allowing re-analysis and data-mining for vocalisations of certain target species (my personal interest: Orthoptera). However, it seems there is no federated database allowing one-stop access to distinct servers - acoustic data servers are fragmented, or even unstable, and I did not even find a comprehensive list of available sites.
The mean processed signal to noise ratio was calculated to be 30 dB for the Raytheon sonar, and 13 dB for the Klein sonar. Using the Receiver Operating Characteristic (ROC) curve displayed (figure with calculations from Urick,1983 is attached: file name is "ROC curves calculations.bmp"), and given the desired false alarm probability of 0.5%, the probability of detection corresponding to the mean processed signal to noise ratio for each sonar
was calculated at the false alarm level. The probability of detection was calculated to be 0.998 for the Raytheon sonar (green lines on the plot attach