Play song with ultrasonic sensor (TCT40 - transmiter) and amplifier (TC4427)

Thread Starter

Counya

Joined May 16, 2022
4
Hello everyone,
I make this post because I need help to play audio with my Arduino and these components, I've seen this video (
) and I would like to do the same.

My components list :
- Arduino Uno
- Amplifier (TC4427)
- Transductor (TCT40)

The main problem is how to reduce the frequency of the transductor to be able for human to hear the sound.

Thanks in advance for the help
I'm staying available if you need more information

Hugo
 

Thread Starter

Counya

Joined May 16, 2022
4
It is somewhat like an ultrasonic driven Theremin controlled by Arduino.
Search · arduino theremin (github.com)
Hi thank you for you answer, maybe my explication was very bad sorry, I wouldn't play with my ultrasonic sensor, I would like to diffuse song with it, I send with my Arduino a sound to my transductor, and it play this sound.
I saw the Theremin, is more like play music with the distance of the ultrasonic sensor.
 

SamR

Joined Mar 19, 2019
4,194
You do realize that "Ultrasonic" is ABOVE the normal human hearing max frequency. Ultrasonic is typically in the 40-50kHz range and most people cannot hear 10kHz and above. You might play it, but you couldn't hear anything... Hence I suggested the Theremin. Audible range is ~40Hz - ~10kHz.

And, Welcome to AAC!
 

Audioguru again

Joined Oct 21, 2019
4,671
The "Ultrasonic Laser" produces an extremely high frequency ultrasonic beam that cannot be heard. When the beam hits you or an object near you then in makes lower frequency interference that can be heard by you. They say that the sound fidelity heard is not hifi but can be used for old telephone quality speech.

You posted a You Tube video that might be faked and not work. You can by a manufactured very expensive product that works well and is used in museums and in conferences for language translation.
 

MrSalts

Joined Apr 2, 2020
1,762
I built a 44.1kHz triangle wave generator and used that as a reference signal to compare with an audio signal to create a PWM signal - it modulated a laser (transmitter) that could hit a target about 15 meters away. The receiver was very simple (reverse biased red diode) and amplified with a simple op amp circuit then fed into an inexpensive Sony amplifier. We had a box where kids could put their hand in a slot to block the laser pointer beam and cut the voice of their parent/friend/sibling at the transmitter.

It was at the Liberty Science Center for a few months when my company sponsored an exhibit space in the early 2000s.
 

Thread Starter

Counya

Joined May 16, 2022
4
Thank you for your answers, I find 2 more video on YouTube, where some people can send some sound by the transmitter
and

But I still don't understand, how can I reduce the frequency of the transmitter output, you told me "When the beam hits you or an object near you then in makes lower frequency interference that can be heard by you." but without hit object or person, is not possible ?

Maybe it'll be easier to use a real speaker than an ultrasonic sensor.
 

MisterBill2

Joined Jan 23, 2018
11,876
Certainly it is possible to amplitude modulate an ultrasonic frequency signal, and then detect the amplitude changes, just like AM broadcast radio. It would be directional to some degree. Such a signal would be hard to detect if it's presence was not known.
It would also be possible to frequency modulate an ultrasonic signal and then demodulate it using a phase locked loop. But I am not sure where the arduino would be used in the process.
This sounds very much like a " Nuts and Volts" project intended to sell arduino products when a dollar worth of components could do the same thing.
 

Thread Starter

Counya

Joined May 16, 2022
4
Certainly it is possible to amplitude modulate an ultrasonic frequency signal, and then detect the amplitude changes, just like AM broadcast radio. It would be directional to some degree. Such a signal would be hard to detect if it's presence was not known.
It would also be possible to frequency modulate an ultrasonic signal and then demodulate it using a phase locked loop. But I am not sure where the arduino would be used in the process.
This sounds very much like a " Nuts and Volts" project intended to sell arduino products when a dollar worth of components could do the same thing.
Yeah you right, the speaker is available but very expensive like 200$ (SoundLazer), exactly the speaker which I want, but I would prefer to do some search to make my own "directional speaker" or "Parametric speaker", I begin to understand a little the electronic side but the audio side is still dark/unclear.
 

Ya’akov

Joined Jan 27, 2019
5,656
My understanding of parametric speakers is they depend on amplitude modulation and the non-linearity of the air. The 40KHz signal is the carrier wave, and when it interacts with the air the result is something like a square law diode detector. The sum/difference result is filtered by the low pass filter inherent in the human ear. The high frequencies are not perceived but the lower, hearing range, modulating frequencies are.

So you get a highly directional acoustic “beam” of AM 40KHz carrier that is demodulated with acoustical heterodyning to turn the modulation into a distinct, audible acoustical signal in the path of the original signal.
 
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