Yes. The IoT SoundSensor™ is calibrated before shipping and comes with a factory calibration. Regular sound level calibrations can be done with a Calibrator. In Dashboard+ measurement deviations can be corrected.

The IoT SoundSensor’s frequency response is calibrated to be within +/- 2db at the factory, at the moment this can only be done by SensorTeam. Periodical sensitivity calibration can be done yourself with a standard calibrator which is coupled onto the microphone and produces a 1kHz tone at 94 or 114 dB(A/C). The sensitivity offset can be adjusted in the settings of the sensor in our dashboard.

No yet, but the IoT SoundSensor™ is calibrated equal to class 1. This is according tot the calibration report.

dB(A) fast
dB(A) slow
dB(C) fast
dB(C) slow

On Wikipedia you will find more information about the meaning of different sound measurements and weighting.

Yes, the diameter of the microphone is 1/2″ and suitable for a normal portable sound calibrator.

A calibration can be done with any mobile phone on SensorTeam cloud platform. Of course you need a portable sound calibrator to do this.

Yes, the calculation is completely separate

Yes, both are a single sample of the measurement interval.

The IoT SoundSensor™ V3.02 has no RTC on board and the timestamp of the GPS is not always present, so we use the timestamp from the LoRa message itself. Not only national LoRa providers, but also TTN sends a timestamp in their message which can be used.

Hereby a link to the TTN forum: https://www.thethingsnetwork.org/forum/t/gateway-timestamps-in-uplink-metadata-how-calculated/23703/7

We do not buffer the measurement data locally on the sound sensor. Due to the maximum duty cycle we only can transmit once every minute.

Every message sent contains the maximum amount of data already. Meaning there wouldn’t be enough bandwidth left to send buffered data once the connection is restored.

The LoRa network is not suitable for sending large data packages such as WAV. That is why we only send the sound pressure in decibels every minute. We have, however, developed a technical blueprint in which the IoT SoundSensor™ sends audio fragments via LTE-M. If you sign up for our newsletter we will keep you informed of this development.


€ 12,50 (ex VAT) per sensor per month and a free user account.

Nothing, you just need the (Android) app and under ‘Support’ you will find all the information about the payload description, cloud dashboard endpoint and how to connect the sound sensor to any LoRa network.


Currently we have one version of the sensor, which is meant for outdoor use. However, the IoT SoundSensor™ can be used indoor as well.

In order to use the IoT SoundSensor™ indoor slide the switch on the PCB from ”BAT” to ”USB” inside the sensor. Remove the impact cap on the right side of the sound sensor and connect the USB cable (included) with the USB-B female port. Power: 5V DC

The battery and solar panel will be switched off as a result.

Yes, body and microphone are 100% waterproof and weatherproof.

1. Check if the top cable glands are tightened (microphone and solar panel). Hold the base of the gland with a C-wrench, wrench or pliers wrench to prevent the nut on the inside from coming loose. Tighten the top compression nut.
2. Check if the vents are tightened (looks like a bolt, hexagonal shaped). This vent should be as tight as you can get it by hand, or tighten carfully with tools using low force. This is in order to prevent damage to the silicone seal.
3. Check if the PCB is still corrosion free. Corrosion marks are white/greenish and can be found on and around solder joints or other bare metal parts.
4. Check if the foam lid seal is still in place and damage free.
5. Check if the brass M4 threads for the lid have not been pulled out.
6. Mount the lid with 1Nm to prevent damage to the M4 threads.

LoRa network

1. Before the IoT SoundSensor™ can communicate via The Things Network, you will need to register it.

2. Download the LoRa Key and Monitor App from Google Play for network settings (LoRa keys) and connect the sound sensor to The Things Network.

To connect the IoT SoundSensor™ download the LoRa Key and Monitor App from Google Play for network settings (LoRa keys) and connect the sound sensor to The Things Network.

1. Your local provider will deliver the LoRa network keys.

2. Download the LoRa Key and Monitor App from Google Play for LoRa network settings (LoRa keys) and connect the sound sensor to your privaye LoRa network.

We have developed a technical blueprint in which the IoT SoundSensor™ sends audio fragments via LTE-M. If you sign up for our newsletter we will keep you informed of this development.

1. You will need the following endpoint: https://gateway-dot-sensorteam-io.appspot.com/api/sensor/data/sound

2. The login details are sent securely by email after ordering the IoT SoundSensor™.

The internal clock is not accurate enough to be set once and to generate the timestamp from continuously. The internal clock needs to be synchronized and for this we are using the GPS time. Time sync works even when GPS is set to “off” or “once”. 

We do not use the LoRa time from the message received in the gateway, because this is not the timestamp of the measurement itself.

Mobile app

You need a USB-B male to whichever USB connector your (Android) mobile phone is using. Most common at the moment is C male or Micro-B male.You need a USB-B male to the USB connector of your (Android) mobile phone to the IoT SoundSensor™. Most common at the moment is C male or Micro-B male.

A USB-B male to USB-C male cable is included.

No, not yet (Android only). We are working on it.


The GPIO pins are not made available to be programmed by the user. We can program these upon request.

No, we are using an Atmel microcontroller with a certified LoRa module.


You can check the performance of the solar panel of the IoT SoundSensor™ in your region with in easy to use online tool. Below you will find the link to this tool and the necessary steps to make the calculations of solar power production of the panel in your own city or region.

Please follow the next steps:

  1. Select your geolocation on the map at the right.
  2. Select OFF-GRID in the middle.
  3. Fill out:         
    • Solar radiation database: PVGIS-CMSAF
    • Installed peak PV power [Wp]: 9,2 Wp
    • Battery capacity [Wh]: 72 Wh 
    • Discharge cutoff limit [%]: 40%
    • Consumption per day [Wh]: 0,17 W
    • Upload consumption dataSlope [°]: 35°
    • Azimuth [°]:
  4. Click on the button “Visualize results” to see the power production and battery performace of the solar panel in your region. Results appear underneath the webpage.

We use a 6V lead acid battery. Below you’ll see the state of charge percentage related to the voltage measurement.

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