Introduction: Ear Sound Protector

The aim of this project is design and implement a system using combination of arduino components making a wearable product that can be adapted to the human body without harming the person. In this case, our project bases in an ear protection system when someone is in a place where the level of decibels is very high and it is harmful to health.

The decibel level of a normal conversation is approximately 60 decibels. From 100-120 decibels it begins to be a harmful sound to the human hearing. These loud sounds are almost imperceptible to the human hearing, the people don’t realize the damage that is causing to his eardrums. This wearable system have two functions: the first one is detect the level of decibels that is in the environment. The second function is to warn the person of the danger and help to avoid pain as much as possible because it covers the ear.

The sound sensor module of Arduino does not have enough quality to detect such high sound levels, it only detects up to 65 decibels. For this reason the decibel values have been scaled in half.

Step 1: Get the Components


·Arduino - Open-source electronic prototyping platform enabling users to create interactive electronic objects.

·Breadboard - Construction base for prototyping of electronics. It has been used to connect all the electronic components of the project.

·Jumpers - Electrical wire, or group of them in a cable, with a connector or pin at each end, which is normally used to interconnect the components of a breadboard without soldering.

·Resistors 220Ω - Passive two-terminal electrical component that implements electrical resistance as a circuit element. Used in this projects with the pnp transistor.

·NPN transistor PN2222 - It is a NPN bipolar junction transistor. It is used as a switch to control a load at a voltage other than Arduino.

·Sound sensor module - This element provides an easy way to detect sound and is generally used for detecting sound intensity. Detects up to 65 decibels, a noise higher than a normal conversation.

·Air pump - This auxiliary element can pump air into your soft robot. It’s the element with which we will inhale the ballon.

·USB Cable - The system power supply (5V). Connect the Arduino UNO board with the computer.


· 3D Machine - We need a 3D machine to print the ear. The material and color of the filament is not important, you can choose the one you like best.

· PVC pipe Ø 4 mm - The PVC pipe connects the air pump with the balloon so the pump does not have to be inserted into the ear.

·Ballons - It is the element that is inserted into the ear and when there is a loud sound it is incised with the air of the pump and blocks the ear hole.

·Silicone - To paste the tube to the ear.

Step 2: Mounting the Prototype and the Circuit

1. First of all look for an ear in three dimensions on the Internet. Web pages like Grabcad let you download 3D documents for free.

2. Print with your 3D machine the ear in .stl, in our case we have made the ear in double scale. This process will take about 5 - 9 hours.

3. While the ear is printing, we can go making the circuit. To assemble the circuit the first time use the arduino protoboard as a base, then we will weld the different components on a bakelite board.

4. First we will assemble the circuit where the Sound sensor module is located. We will need a resistor, the Sound sensor module and different jumpers to connect it to the arduino board.

5. The Sound sensor module detects up to 65 decibels, for this reason a "simulation" will be done and we will scale the actual value of decibels in half. 65 decibels will be equal to 130 decibels which is a very damaging sound to the ear.

6. You can check the correct functioning of the code and circuit by putting a LED light (when it turns on it means that the decibel level has exceeded the level that we have indicated in the code).

7. Second, we assemble the air pump circuit. In this circuit we need an NPN transistor, the air pump, pvc pipe, a ballon and some jumpers. In our case, the pump used is 6V and we use the Arduino power supply (5V). If the pump is of a higher voltage you can use a external battery.

8. Once the two circuits work correctly separately, we join the two codes.

9. We welded the elements we had on the breadboard on a bakelite board.

10. We introduce the balloon into the ear hole and paste the pvc pipe behind the ear with silicone. We test several times the good functioning of the program and regulate the duration of the pump throwing air so that the balloon covers the entire hole of the ear without sticking.

11. Finally, you can already simulate your wearable!

Step 3: Schematic of the Circuit

Step 4: Programming

In order to get the Ear sound protector to be interactive, we must write a code with the Arduino program, and later on it must be uploaded to our Arduino One.

Here is our code for this project:

<p>int SoundSensor = A0; // pin the sound sensor is attached to.<br>int volum = 0; // variable to know the amount of noise the sensor receives.
int aire = 13; // pin the air pump is attached to.</p><p>// the setup routine runs once when you press reset:
void setup() {
  pinMode(aire, OUTPUT); // sets the air pump as an input.
  Serial.begin(9600); // starts the serial communication.
}</p><p>// the loop routine runs over and over again forever:
void loop() {
  volum = map(analogRead(SoundSensor), 0, 1023, 0, 180); // the analog number received by the sensor changes to a decibels scales from 0 to 180.
  Serial.println("Decibels:"); // prints "Decibels:" in the monitor serie.
  Serial.println(volum); // prints the number of decibels, read by the sound sensor, in the monitor serie.
  delay(100); // sets a delay of 0,1s between each reading of sound.
  if (volum >= 90) { // check if the decibels received by the sound sensor are equal or higher than 90. If it is:
    digitalWrite(aire, HIGH); // the air pump turns on.
    delay (3000); // sets a delay of 3 seconds before the air pump turns off.
    digitalWrite(aire, LOW); // the air pump turns off.

Step 5: Video

Step 6: FInal Conclusion

This project has allowed us to design a wearable, an electronic system combining electronic components that we had worked in class and with new ones. This systems propose a solution for a problem that harms people's health

Apart from designing a correct circuit with all the connections made in the breadboard and program the code in the arduino, think about how to solve the problem designing a wearable was the most complex part of the project. With this project we have done research on a thematic that we had never done that is wearable products. With this project we realize that in the future we can make fast prototypes with the arduino board.