Acoustic Communiaction References

[Jiggy-Ninja]

I'm doing a research paper about electronic wireless communication using sound. I've got a few reference regarding its use in underwater networks, networking within a body in a medical context, and one regarding communicating information through a steel wall (such as a sealed pressure vessel).

I've not been able to find much of anything on consumer level devices. I believe I saw a reference on this forum as well to using ultrasound through the PA system of a building for automation purposes of some kind or something like that. I do not know if this was a hypothetical example or something that has actually been implemented by anything.

If you know of any references regarding audio data communication being used in consumer devices or home/office/public building automation context, please point me to them.

NOTE: This paper is specifically about data communication. Ultrasonic imaging, range finding, and motion detection are not appropriate for the topic.

 

[berkeman]

There used to be two kinds of TV remote controls -- IR and ultrasonic. I haven't seen the ultrasonic ones in many years, but you may still be able to find out what data encoding scheme they used.

Then there is Morse Code, sent by various means.

Does whales communicating underwater over large distances count?

 

[Jiggy-Ninja]

There used to be two kinds of TV remote controls -- IR and ultrasonic. I haven't seen the ultrasonic ones in many years, but you may still be able to find out what data encoding scheme they used.

Then there is Morse Code, sent by various means.

Does whales communicating underwater over large distances count?

Didn't the ultrasonic ones just have tuning forks? Or were there some with an actual transducer and a modulation scheme?

Morse code, by my understanding, isn't usually transmitted with sound as the carrier, usually radio or wire. Do you have a specific implementation in mind, or just as example?

Whales are not electronic, so they don't count. I already planned on noting them as biological "prior art" in the beginning of it.

The requirement for the assignment topic is pretty broad: just has to be about any wireless communication technology. Some of the example topics are WiMAX, Bluetooth, Near Field Communication, 3/4G, etc. I chose sound because it's a bit more exotic than any of the suggestions. So I'm looking for technologies that use sound waves as the actual method of transmission, whether through gas, liquid, or solid.

 

[jim hardy]

I believe I saw a reference on this forum as well to using ultrasound through the PA system of a building for automation purposes of some kind or something like that. I do not know if this was a hypothetical example or something that has actually been implemented by anything.

That might have been me..
Around fifteen years ago I built a gizmo to tell which of our PA stations was active at any time. I mentioned it in a thread about PLC's, to encourage a young fellow to experiment.

If you have interest - I did it with 1970's technology.
Quick summary -
We had folks playing on the PA system - wolf howls at the girls and one fellow who sang opera.
To track which station was active at any time we built a small circuit board to add to each PA station's amplifier. The board was about size of a cigarette pack.
The board used TP5088 Touch Tone(DTMF) generators to produce a pair of tones unique to each station. Each tone modulated an ultrasonic carrier, I used 22 and 28 kHz carriers. I used LM566 or 567 PLL's, no longer recall which.
The carriers were capacitively coupled into the PA system's voice line by a LM386 audio amp.
The circuit board transmitted the tones in ~half second bursts whenever its particular PA station was active.
DTMF is HEX based , gives sixteen tones, so a two digit system allows 256 unique codes.

One receiver served the whole PA system.
The receiver consisted of an isolation transformer, two narrow band active filters, two FM demodulators and some logic.
The narrow band filters were tuned to the carriers.
Each filter fed a LM567 used as frequency demodulator. It output was one of the DTMF tones from the active station.
Each LM567 fed its demodulated tone to a DTMF decoder IC which produced a 4 bit hex digit and a signal health bit.
Upon receiving two healthy digits, an AND gate awoke a microcomputer which strobed in the digits.
The microcomputer then printed a message indicating time of day and location of the active station. It was one of those Domino's I linked to in the other post.

It worked well over distances of a couple thousand feet, basically all over the plant.
And removing anonymity stopped the abuse.

It was completely home-made.
We had about a hundred of the individual station circuit boards built by a local electronics shop.
Only one receiver was ever built, to my knowledge. I etched the board in my kitchen sink

There exists a patent by a fellow at a nuke plant in Georgia to achieve similar result. He placed commercial modems in each PA station. I stumbled across it at USPTO dot gov ...

I hope this is some help. Amusing anecdote, at least...
Nowadays one would use PIC microcontrollers.old jim

 

[berkeman]

Morse code, by my understanding, isn't usually transmitted with sound as the carrier, usually radio or wire. Do you have a specific implementation in mind, or just as example?

Whales are not electronic, so they don't count. I already planned on noting them as biological "prior art" in the beginning of it.

Well, I guess people aren't electronic either, so using the example of people tapping out Morse Code to get rescued in collapsed buildings wouldn't work, eh? And the POWs in Vietnam prisons had a similar tapping communication mechanism, to pass messages through cell walls.

 

[berkeman]

Didn't the ultrasonic ones just have tuning forks? Or were there some with an actual transducer and a modulation scheme?

I did a quick Google search, and you are correct that the first "Zenith Space Command" ultrasonic TV remote controls used 4 tuning forks to send out the US commands to the TV. But as transistors became available, the tuning forks were replaced by solid state electronics. You can do a similar search to find out the details...

 

[berkeman]

BTW, foghorns may qualify for your category...

And "ring-down" tones in fire stations and ambulance companies (the different tones signify a different kind of emergency call is about to come in over the radio/PA system...

And maybe the different ring tones for cell phones, that tell you if you have a text message or a call coming in, and even who the caller may be (if you assign different ring tones to different friends)...

And the different error/busy/ringing tones that you hear when you make a phone call...

 

[berkeman]

Oh, and emergency vehicle sirens...

(Some of the newer siren systems are impressive. They can make your vehicle sound like 2-3 different vehicles all traveling together. That helps to clear a path through the brain-dead drivers...)