This work presents the evaluation of a practical experience on noise pollution based on the use of smartphones to check if it helps students to better understand the concepts related to this phenomenon. This evaluation has been done with a pre-post design in which 112 students, enrolled in the "Physics and Chemistry" course of the 1st year of non-compulsory high school, have first filled in a diagnostics questionnaire with 5 free response questions about their knowledge on the topic and then a pre-post questionnaire with 4 free response questions. The results show that the proposed practical experience is effective since a statistically significant improvement is obtained both globally and in each of the questions of the questionnaire. The practical experience has also been highly valued by 38 students enrolled in the "Physics and Chemistry" specialisation of the Master in Secondary Education Teaching.