{'fraction_non_alphanumeric': 0.0137524557956778, 'fraction_numerical': 0.0, 'mean_word_length': 5.52991452991453, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Suppression and analysis on annoyance of motor vehicle noise using water sound injection

Different from the traditional noise control approaches based on sound energy reduction, this study focuses on the annoyance suppression of motor vehicle noise based on audio injection. Firstly, eight motor vehicle noises were selected as the target sounds and three different controllable sounds were used to overlap with different signal-to-noise ratios. Then absolute threshold and combined sound annoyance subjective evaluation experiment were carried out to obtain absolute threshold range and the existence zone of "destructive effect" for combined noise annoyance. Next the influencing factors of the destructive effect are analyzed. The results of the study found that the identifiability of the target sound and the controllable sound is important to the selection of the controllable sound. For most target sounds with high identifiability, the controllable sound with high identifiability and high SNR should be selected. For most target sounds with low identifiability, the controllable sound with low identifiability and low SNR should be selected. Moreover, after the addition of optimal controllable sound, the descend value of the annoyance degree of the target sound with high identifiability is lower than that of the target sound with low identifiability. The results will also provide guidance for the research on audio injection effects, physical mechanisms, the controllable sound selection and optimization design.