DIY ELECTROLARYNX WITH ARDUINO NANO

by RaulMontero in Circuits > Assistive Tech

50 Views, 0 Favorites, 0 Comments

DIY ELECTROLARYNX WITH ARDUINO NANO

WhatsApp Image 2025-12-06 at 13.43.15.jpeg

An electrolarynx is a device used by people with tracheostomies to regain the ability to communicate through “voice,” using mechanical vibrations generated by the device as a substitute for the vocal cords.

The goal of this project is to design an apparatus similar to low-cost commercial models for individuals who need it but cannot afford existing devices on the market due to their high cost.

Supplies

Captura de pantalla 2025-12-07 105637.png

List of materials for the creation of this project:

  1. Soldering station
  2. Solder wire (tin/lead or lead-free)
  3. Arduino Nano
  4. Contact transducer or tweeter (in my case, a tweeter taken from a Mackie CR5BT studio monitor)
  5. PAM8403 amplification module
  6. Breadboard or PCB
  7. Connecting wires for soldering

SOLDERING THE WIRES TO THE PAM8403 MODULE

WhatsApp Image 2025-12-07 at 11.09.50.jpeg

The nodes present on the module, starting from the left, are:

- Rout + + Lout - - Power + L G B

  1. The two terminals of the selected transducer or tweeter are connected to the “+” and “−” nodes of Lout (alternatively, the transducer can be connected only to Rout).
  2. Two wires are soldered to the “+” and “−” Power nodes.
  3. If Lout has been selected, two additional wires are soldered to the L and G nodes.

To allow testing of different transducers in order to improve the sound quality of the electrolarynx, the wires were connected using alligator clips instead of being soldered directly to the PAM8403 module.

ARDUINO IDE CODE

After connecting the Arduino Nano to the computer, open the Arduino IDE, select the appropriate board, and proceed to edit the code. Enter the following code:

const int salidaAudio = 3; // Pin conectado al PAM8403
const int frecuencia = 120; // Hz (electrolaringe)

void setup() {
pinMode(salidaAudio, OUTPUT);
tone(salidaAudio, frecuencia);
}

void loop() {
// No se necesita nada aquí
}

The selected frequency is intended to simulate the human voice, whose frequency range is approximately 80 Hz to 180 Hz. For the Mackie CR5BT tweeter, 120 Hz provides the best sound quality.

The Arduino pin used (pin 3 in this case) can be replaced with any preferred digital output pin.

Finally, click the compile button and upload the program to the microcontroller.

CONNECTIONS ON BREADBOARD OR PCB

Captura de pantalla 2025-12-06 134806.png
  1. Connect the GND (ground) nodes so that both the PAM8403 module and the Arduino share a common ground.
  2. Supply the module with 5 V by connecting it to the “+” Power node.
  3. The L node is connected to the pin selected in the code, which in this case is D3.
  4. Finally, connect the transducer to the module using the Lout − / + nodes.

TESTING THE ELECTROLARYNX

WARNING

If the user has any medical condition, consult a healthcare professional before prolonged use. This is a homemade, experimental device and not a certified medical device.

Place the transducer on the area of the neck that best transmits vibration toward the mouth, and make an effort to articulate as clearly as possible to improve speech intelligibility.

Do not leave the device on the neck for extended periods. If discomfort occurs, a silicone pad or dressing may be placed between the transducer and the skin.