KY-037 Microphone Sound Detection Sensor Module – Analog & Digital Sound Sensor for Arduino & ESP32

The KY-037 Microphone Sound Detection Sensor Module is a compact electronic sensor designed to detect sound levels and acoustic events in the surrounding environment.

Featuring a high-sensitivity electret microphone and LM393 comparator circuit, the module provides both analog and digital outputs, allowing microcontrollers to monitor sound signal variations and detect when sound exceeds an adjustable threshold.

The KY-037 is ideal for Arduino, ESP32, Raspberry Pi projects, sound-activated switches, robotics, clap detection experiments, noise monitoring, and interactive electronics.

With its adjustable threshold and easy-to-use interface, the KY-037 is a practical solution for educational projects and basic sound-triggered automation systems.

Key Features

• Model: KY-037
• Sensor Type: Microphone Sound Detection Sensor
• Microphone Type: Electret Condenser Microphone
• Comparator IC: LM393 or Compatible
• Output Types: Analog (AO) and Digital (DO)
• Operating Voltage: Typically 3.3V–5V DC, Module Dependent
• Adjustable Digital Sound Detection Threshold
• High-Sensitivity Microphone
• Onboard Sensitivity Adjustment Potentiometer
• Onboard Power and Detection Indicator LEDs
• 4-Pin Interface: AO, GND, VCC, DO
• Compact PCB Design
• Suitable for Arduino, ESP32, and Microcontroller Projects

Technical Specifications

Pin Configuration

Note: The physical order of the pins may vary between manufacturers. Always follow the labels printed on the supplied module.

How It Works

The KY-037 uses an electret microphone to convert sound waves into small electrical signals.

When sound reaches the microphone, the resulting electrical signal changes according to the acoustic vibrations.

The module processes this signal and provides two output options.

Analog Output (AO)

The analog output provides a varying electrical signal associated with the microphone's response.

A microcontroller with an analog-to-digital converter (ADC) can sample this output to observe sound-related signal changes.

The signal is not calibrated in decibels and may be small or noisy depending on the module design.

Digital Output (DO)

The LM393 comparator compares the microphone signal with a threshold set by the onboard potentiometer.

When the signal crosses the selected threshold, the digital output changes state.

This allows the microcontroller to detect sound events without continuously processing the analog signal.

The potentiometer adjusts the digital detection threshold; it does not necessarily amplify the analog microphone signal.

Arduino Connection Example

This connection allows the Arduino to monitor both the analog microphone output and the digital sound detection signal.

Arduino Example Code

const int analogPin = A0;
const int digitalPin = 2;

void setup() {
  pinMode(digitalPin, INPUT);
  Serial.begin(9600);
}

void loop() {
  int analogValue = analogRead(analogPin);
  int digitalValue = digitalRead(digitalPin);

  Serial.print("Analog Sound Value: ");
  Serial.print(analogValue);

  Serial.print(" | Digital Output: ");
  Serial.println(digitalValue);

  delay(10);
}

This example reads the analog and digital outputs and displays the values in the Arduino Serial Monitor.

To test the module, make a sound near the microphone and observe the readings. Adjust the onboard potentiometer to change the digital detection threshold.

Important: The digital output polarity may vary between module versions. Confirm the active state using the onboard indicator LED or by testing the output.

Applications

• Arduino and ESP32 Sound Detection Projects
• Sound-Activated LED Indicators
• Clap-Activated Switch Experiments
• Robotics and Interactive Systems
• Basic Noise Event Detection
• Sound-Triggered Alarms
• Electronic Prototyping
• Educational STEM Projects
• Interactive Lighting Systems
• DIY Home Automation
• Acoustic Event Detection
• Microcontroller Sensor Experiments

Important Notes

• The KY-037 is a sound detection sensor, not a calibrated sound level meter.
• It cannot directly measure sound pressure levels in dB or dBA.
• The analog output is not intended for high-quality audio recording or speech recognition.
• The digital output indicates threshold crossings rather than providing a numerical sound level.
• The onboard potentiometer adjusts the comparator threshold.
• Background noise, electrical interference, and microphone orientation can affect detection performance.
• The module may generate multiple digital pulses during a single clap or sound event.
• Software filtering or event debouncing may be needed for reliable clap detection.
• The analog signal may require amplification or additional signal processing for advanced audio applications.
• For ESP32, ensure the module's outputs remain within the 3.3V input limits.
• Raspberry Pi GPIO pins are not 5V tolerant. Use suitable level shifting when required.
• Raspberry Pi boards require an external ADC, such as the MCP3008 or ADS1115, to read the analog output.
• For accurate noise measurement, audio recording, or voice recognition, use a dedicated calibrated microphone system or suitable digital audio microphone instead.

Package Includes

1 × KY-037 Microphone Sound Detection Sensor Module