Outdoor NOise MOnitoring system

Smart noise measurements


VTT Technical Research Centre of Finland
Panu Maijala (panu.maijala@vtt.fi)


Toni Heittola (toni.heittola@tuni.fi) Tampere University


Panu Maijala, Toni Heittola, and Tuomas Virtanen. Ympäristömelun mittaaminen käyttäen automaattista lähteiden tunnistusta. In Akustiikkapäivät 2019, 196–206. Oulu, Nov 2019. PDF

Panu Maijala, Zhao Shuyang, Toni Heittola, and Tuomas Virtanen. Environmental noise monitoring using source classification in sensors. Applied Acoustics, 129(6):258–267, January 2018. PDF


Onomo is a product of a joint project between Tampere University, VTT Technical Research Centre of Finland. Onomo provides intelligent noise measurements for various type of auditory scenes. The system is capable of classifying noise sources and thus will give more accurate measurement of real noise produced by the target site. This page is a visualization front-end for the prototype system.

Continous measurement

The prototype system is collects continuous sound pressure level measurements. The system consists of Onomo device which is are doing noise measurements noise type classification 24/7. In the device, there is a small computer and measurement microphone. Sound pressure level measurement are done in one minute intervals.

Noise source classification

The noise source classification system classifies the measurements into three classes: one containing mostly sound from the target (e.g. rock-crushing), one containing mostly normal environmental sounds and one containing mostly abnormal sounds. Abnormal sound are the sounds which do not belong to any of the two other classes. By classifying the signal into segments, the sound pressure level measurements can be better targeted.

Noise classification system has been developed by audio research group at Tampere University.