Environmental noise affects life and health within urban environments through interfering with sleep, rest, study and personal communication. Noise mapping is an important issue of local authorities but due to its requirements (staff, costs and frequency), the available data are limited or outdated. Our aim was to involve people with smartphones in the mapping process and to determine the accuracy of the measurements performed with these devices in a natural environment. The main questions were whether the measured data were dependent on the type of applied software and smartphones. We tested three software (Noise Watch, Noise Meter and Sound Level Meter) and 12 different smartphones. We evaluated the measurements with hypothesis testing and correlation analysis. Although the accuracy of smartphones was below the professional equipment, measurements can be conducted easily due to their availability; thus, a reliability analysis is important. We found that comparison between professional devices and smartphones in a laboratory was misleading as it lacks the environmental factors biasing the measurements. The best method to compare the measurements carried out with smartphones and professional Noise Meters was to use large number of measuring points in a heterogenic outdoor environment where the noise ranged from the low to large values. We revealed that both the applied software and smartphones have relevant effect on the measurements, and, although it is possible to use these devices for noise mapping, one should consider not to apply different software and smartphones. Accordingly, crowdsourcing is not a reliable data collection method because: (1) measurements should be supervised, (2) smartphones’ accuracy should be tested and (3) measurement circumstances should be the same. If any of these requirements are violated, the quality of the resulting maps can be questioned.

环境噪声会干扰睡眠，休息，学习和个人交流，从而影响城市环境中的生活和健康。噪声映射是地方政府的重要问题，但是由于其要求（人员，成本和频率），可用数据有限或已过时。我们的目标是让拥有智能手机的人参与到地图绘制过程中，并确定在自然环境中使用这些设备执行的测量的准确性。主要问题是测得的数据是否取决于所应用软件和智能手机的类型。我们测试了三种软件（噪音监测，噪声计和声级计）和12种不同的智能手机。我们通过假设检验和相关分析评估了测量结果。尽管智能手机的准确性低于专业设备，由于其可用性，测量很容易进行；因此，可靠性分析很重要。我们发现，实验室中专业设备与智能手机之间的比较具有误导性，因为它缺乏使测量结果偏颇的环境因素。比较使用智能手机和专业噪声计进行的测量的最佳方法是在异质室外环境中使用大量测量点，在异质室外环境中，噪声的范围从低到大。我们发现，所应用的软件和智能手机均会对测量产生影响，尽管可以将这些设备用于噪声映射，但应该考虑不要使用其他软件和智能手机。因此，众包不是一种可靠的数据收集方法，因为：（1）应监督测量，（2）应测试智能手机的准确性，（3）测量环境应相同。如果违反了任何这些要求，则可以质疑生成的地图的质量。