Acoustic Communication - Science topic

Look at https://tetcos.com/underwater_networks.html

Unfortunately not in my field of expertise. My main expertise is in Acoustics relating to assessment and prediction of environmental and building acoustics and the same for ground borne vibration. You have presumably done an online search on Google for this topic?

Good luck with your research.

Differences in distress: Variance and production of American Crocodile ( Crocodylus acutus ) distress calls in Belize

Visit to that article

Intelligent Reflecting Surface IRS be designed for 1 to 6 GHz bands:

1- Cascaded Channel Estimation for Intelligent Reflecting Surface Assisted Multiuser MISO Systems

2- Terahertz Multi-User Massive MIMO With Intelligent Reflecting Surface: Beam Training and Hybrid Beamforming

3- Wireless Environment as a Service Enabled by Reconfigurable Intelligent Surfaces: The RISE-6G Perspective

4- Joint Beam Training and Positioning for Intelligent Reflecting Surfaces Assisted Millimeter Wave Communications

5- Intelligent Reflecting Surface (IRS) Allocation Scheduling Method Using Combinatorial Optimization by Quantum Computing

5- A Path to Smart Radio Environments: An Industrial Viewpoint on Reconfigurable Intelligent Surfaces

6- System Performance Insights into Design of RIS-assisted Smart Radio Environments for 6G

7- Slotted Wideband Frequency Selective Reflectors for Sub-6 GHz 5G Devices

The research on IRS design and performance optimization is in its infancy.

IRS intelligent reflective surfaces applications nowadays:

1- IRS-assisted low altitude passive aerial relaying

2- Intelligent Reflective Surfaces for Wireless Networks: An Overview of Applications, Approached Issues, and Open Problemshttps://www.mdpi.com/2079-9292/10/19/2345

3- When Full-Duplex Transmission Meets Intelligent Reflecting Surface: Opportunities and Challenges

4- Full-Duplex Enabled Intelligent Reflecting Surface Systems: Opportunities and Challenges

5- Sum-Rate Maximization for IRS-Assisted UAV OFDMA Communication Systems

Intelligent Reflecting Surface Assisted Multi-User OFDMA: Channel Estimation and Training Design

Hello,

Will you conduct noise level measurements at the soundwalk stops? If so, you could ask about the perceived loudness using a scoring method and then correlate the objective and the subjective results.

Yes, IRS can be deployed to enhance security in communication networks to either replace legacy security solutions or supplement them.

IRS or no IRS, isn't this a standard problem of propagation loss? You have to know the sensitivity of the receiver, the noise power at the receiver, the gain of the receive antenna, the range to the transmitter, the terrain characteristics, and consequent signal loss along the path, and the transmit power and transmit antenna gain.

Now, without IRS involved, you can compute the signal to noise ratio at the receiver, and determine if communications are possible, using a given type of modulation. There will be different marginal SNR requirements, depending on type of modulation you want to use. Shannon's equation can be used, to predict the maximum possible channel capacity, along a single propagation path, with a given channel bandwidth and SNR.

I'd say that using IRS, at either or both ends, is much the same as changing transmit and/or receive antenna gain.

The basic algorithms for phase configuration and channel estimation are described in our tutorial article: https://arxiv.org/pdf/2102.00742.pdf

Dear Abbas Thajeel Rhaif Alsahlanee ,

Welcome!

As far as I understand the IRS is one hop network component. If the path from the source to destination has low transmission coefficient such as deep fading of massive blocking then one can use one ore two IRSs to convey the signal to the intended receiver or destinations.

Incase of more that one IRS all of them receive their incident waves from the intial source such as the base station. I think multi hops may cause excessive delay.

Best wishes.

An IRS is a new type of relay, with specific characteristics, benefits, and drawbacks. This is discussed in our recent magazine article: https://arxiv.org/pdf/2006.03377.pdf

Dear Abbas,

I will recommend the article https://arxiv.org/pdf/2104.01421.pdf

I hope it will be worth reading about your problem.

Yes, you can use the technology at any frequency band and for many different use cases. The main question is what kind of problem the addition of an IRS will solve. One possibility is to deal with Doppler effects: https://arxiv.org/pdf/2006.06991.pdf

Dear Abbas,

I suggest you to see links and attached files on topic.

Best regards

Dear Abbas Thajeel Rhaif Alsahlanee ,

welcome!

It is so that the the signal path from the base station shows multipath effects such as fading to the user site.

The addition of the IRS will introduce an alternative path where the signal will be recieved by the IRS phase shifted and amplitude changed and directed to the the site of the user equipment. So the signal path through the IRS must has better transmission properties which means higher signal to noise plus interference at the user site.

So, Accordingly one has to maximize the signal to noise plus interference ratio.

Best wishes

Adding to the respected colleagues, the IRS are made of a two dimensional array of sub wavelength patches provided by pin or varactor diodes such that one can phase shift and control the amplitude of the reflected wave from each patch.

One can control the phase shift by changing the diode bias. The diode is sufficient to change the phase shift from 0 to pi.

Where you want to insert the filter and why?

For more information please refer to the presentation in the link:https://www.ltu.se/cms_fs/1.203003!/file/Emad%20Ibrahim.pdf

Best wishes

Hi Joni,

I have always referred students who ask about basic acoustic processing in sharks, skates and rays to this now classic paper by Jeff Corwin:

Corwin J.T. (1981) Audition in Elasmobranchs. In: Tavolga W.N., Popper A.N., Fay R.R. (eds) Hearing and Sound Communication in Fishes. Proceedings in Life Sciences. Springer, New York, NY. https://doi.org/10.1007/978-1-4615-7186-5_5

Of course if you are specifically interested in the acoustic "signals" produced by these animals rather than the detection of such signals, then I will keep looking.

Hope this helps.

Peter

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My pleasure Dear Prof Aleksey. Regards

I agree that Audacity is of no use-- it's primarily an editing program, not for measurement. Praat and SAP would both probably work for the simple measurements you described. I believe Praat (which was developed for work on speech) has some tools for measuring speech-related features such as formants, which might be useful for nonhuman primate vocalizations. Raven Pro (http://ravensoundsoftware.com/) has (I'm told) an easier learning curve than Praat and includes basic time, frequency, and relative power measurements (though no formant measurements). There's also a set of freely available tutorial videos available (see "Training" on that website).

There is some advances in this area, e.g. http://www.who.int/medical_devices/innovation/new_emerging_tech_3.pdf

and

Hi Laura,

I agree with Pavel regarding the channels and amplitude. I also don't use SoundRuler (sorry!) but I thought it might be useful to add that you need to be sure there is no background noise overlapping your calls of interest. If for example these recordings were made at a zoo, there may be visitors chatting, or in the field there could be other animals calling etc. on your recordings. If there is, then you can either need to filter it (if it does not overlap in frequency with the monkey calls), or if that's not possible, you could manually extract the frequency measures, or simply eliminate those calls from your analyses. It might be that you can use the read-out on all your "clean" calls (i.e. no background noise, one individual calling at a time) and in that case it could be just as simple as you say!

Good luck with your interesting project!

All the best,

Esther

Please have a look at these links.

Dear fellows,

I've been watching your discussion related to "Do fish measure reactive intensity?" and found it interesting when talking about "total sound intensity from a pure acoustic point of view". When it comes to sound reception/sensing in fish you've forgot the "most" important sensor beside the swim bladder and the lateral line, i.e. the otoliths, which act like an accelerometer. There is some literature related to this which may clarify/elucidate sound reception in fish in relation to total sound intensity. I'll like to see you++ continue with this discussion.

Some of the Wilcoxon sensors were developed with the US Gov't, and have ITAR restrictions associated with them.  They are not available internationally.  Applied Physical Sciences also has some sensors, but they too have ITAR restrictions.  The Microflown/Hydroflown sensors (from the Netherlands) have never been proven to be effective in underwater applications. 

My recommendation would be to get several good pressure sensors and build your own vector sensor based on pressure gradient measurements.  (I believe that's really what the PAS is.)

Imagine your transmitter is isotropic (transmits equal power in all directions) and the medium is lossless. You can now think of the signal as an ever expanding spherical wave front. Because the total power is constant, and the area of the sphere increases with the square of the radius, the signal power at each point of the sphere will be inversely proportional to the square of the radius (their product should be constant). For this reason the signal power at 700m will be (6/7)^2 of the signal power at 600m. The power should therefore be increased by a factor of (7/6)^2 to compensate. This rule is based on the conservation of energy principle and holds for every possible type of radiation (radio, acoustic, light,...)

In reality the transmitter is typically not iostropic but that does not matter, the principle stays the same.

For the case of electromagnetic radiation there is a nice mathematical formula called the "Friis transmission equation". Google for more info.

Good luck with your research!

depends on data which transformation to apply. available in standard texts

as mentioned before there are two problems, storage and batteries. Among small digital recorders the best one is the SONY PCM-M10, unfortunately now discontinued but still available in US. Its power consumption is among the lowest: 60-70mAh, that means >30 days continuous recording with 6 or 8 D size batteries (max 18Ah at 1.5V), that brings weight and size high. As an option you could use Lithium D size batteries, expensive but with double power than alkaline (up to 19Ah at 3.6V).

As for the storage the M10 is one of the very few that is declared max 32GB but can record on a Sandisk Ultra 128GB microSDXC formatted by a PC in FAT32 mode. The max microSD size now available is 200GB but I never tested it in the SONY. Huge size available; however, to record 30 days you necessarily need to switch to MP3-320K with a bandwidth of 15 kHz, that is more than with 22k PCM sampling.

In 22kHz PCM stereo (few recorders can record in mono !) you need 228GB/month that would be possible with a standard 256GB SDXC card (these are also available up to 512GB now). But recorders are larger and more power hungry.

Solutions based on microcomputers need too much power. In any case the first feature you must check is power consumption. A recorder that would partially fit your needs is the Tascam DR22WL, it records in mono and thus 1 month could fit in a 128GB microSDXC card. Unfortunately it requires near to two times the power required by the SONY M10. If you solve the battery problem the WL 22 is the good solution.

Another option to be deeply tested before going on is to use the ZOOM H1. Smaller and lighter than the SONY, It is declared to max 32GB microSD however it can record on larger memories as the SONY (to be tested on specific memory brands and to be tested for power requirements).

Eventually write me privately for alternative options.

Gianni

According to 'Development of fetal hearing' by Peter G Hepper and B Sara Shahidullah, the high frequency range you are interested in was not considered in this study however it says that early in gestation 'none responded to the 1000 Hz and 3000 Hz tones'...so one can extrapolate...but it is all about hearing perception.

Hi Mushtaq 

thank you. I am sorry for late response.

I will try Pulse lab.

There is one paper. It's related to nightclubs though, rather than specifically pubs and bars. http://herd.typepad.com/files/hendrie_etal_2009.pdf There's not much there in relation to music, but it does make the point that because nightclubs are generally quite loud and dark, that it promotes lekking behaviour. (Pg. 1344). There's also a section on dancing displays (Pg 1336).

In Yellowhammer Dialects project, I am exploiting many sources of recordings:) Surprisingly, some yellowhammer song are also on Flicker, however I bet this is not the case of African warblers.

One is on AvoCet (http://avocet.zoology.msu.edu/recordings?scientific_name_search=Acrocephalus+baeticatus&name_search=&Search=Search+Recordings)

The best would be to contact British library - they have about 47 songs: http://cadensa.bl.uk/uhtbin/cgisirsi/?ps=jvO7LMNQhB/WORKS-FILE/325200049/123 I will send you a contact to a responsible person through email, Nika:-)

Mohan, this answer is for the antennas in electromagnetics. The electromagnetic field associated with an antenna is the Fourier Transform of the current aperature distribution of the antenna. This depends greatly on the shape and feed design of the antenna. An added complication is that the time variations of the current introduce solutions to the math that involve a far field and a very complicated near field.

Think of it this way.  The electromagnetic radiation that propagates away from the antenna, never to return, is governed by the far field and obeys the inverse square law for propagation distance. The near field is much more complicated and involves higher order inverses and the fact that the energy in the near field does not propagate. It expands and contracts in response to the frequencies of the excitation current. However the energy is exchanged by the electric and magnetic field as is the normal case of propagation.

I forget the formulas for how far the near field extends from the antenna but I know that the higher the effective gain, the further the near field extends. In some very large gain antennas, the near field may extend 800 meters! Good luck.

Dear Veronika,

You might want to look at Birsong, Speech and Language (Bolhuis and Everaert, 2013).  There's a number of nice pieces in that book and I'd recommend reading ten Cate et al.s' chapter 12:  "Analyzing the Structure of Bird Vocalizations and Language:  Finding Common Ground", where they discuss a variety of techniques.  

Best regards - Marie

Bolhuis, J. J., and Everaert, M. (2013). Birdsong, speech, and language : exploring the evolution of mind and brain (MIT Press, Cambridge, Mass.).

I agree with Charles Henry about anatomical validation. In our lab we have modified a GoPro action camera (which records at 240 frames per second and fantastic resolution) with macro lenses and have been getting incredible "high speed" video of echolocating bats for a fraction of typical high speed camera costs. Contact me directly if you'd like more information on this setup--all the components are available commercially from various companies.

Dear Mir

A communication link consists of a transmitter , a receiver and a communication medium. Every medium has the suitable signal energy form to propagate easily in it.

Good electricity conductors such as metals are conveyor of electricity.Therefore transmission lines are made from metallic conductors like copper and aluminium.It is not practical to connect the transmitters and receivers in underwater by transmission line.

Therefore one uses the suitable wireless system for under ware communication.

Basically there are two basic wave types, the acoustic waves and the electromagnetic waves. Sea water is salty and therefore good conducting as Dr Garry mentioned. Consequently it attenuates the electromagnetic waves and this attenuation increase as the frequency increases. Only low frequency electromagnetic waves are capable to propagate an appreciable distance before it gets undetectable.Therefore the radio wave under sea water communication is restricted to very low frequency waves with very small band width and consequently very low data rates. Newly, short distance under water optical communication links are developed operating in the wavelength range from 0.4 to 0.55 micrometers.They can be considered also wireless electromagnetic wave communication.

As a medium the sea water as a fluid is suitable for acoustic wave propagation. Therefore, the under water communication systems are normally

based on acoustic wave transmission. Here piezo electric transducers are used to convert the electrical signal into acoustic waves and vice verse. The rest of the system remains the same.

As a communication medium its carrier frequencies are limited and consequently the

channel bandwidth. The power is limited because it is mostly battery operated system. The propagation speed is relatively small and hence larger delay time and delay time spread. Therefore, the link data rate is relatively small and limited.

From the principle point of view, OFDM can be used as a modulation technique to overcome multipass fading. occurring also in acoustic wave communication.

For more details please see the paper in the link:http://edge.rit.edu/edge/P14251/public/WorkingDocuments/EfficientCommInUWAcousticNetworks.pdf

120 dB is one watt per square meter. I leave you to figure it from there.