Inclusion Criteria:  18 years or older a total score less than 16 on the Leicester Cough Questionnaire chronic daily expectoration over at least 3 months being in a period of clinical stability during the previous 4 weeks presenting a forced expiratory volume in 1 second (FEV1) value greater than 40% of predicted or >1 L obtaining informed consent.  In addition, all participants will have had to satisfactorily pass the tolerability tests, which will be performed twice: i) on the first day; ii) and the following week.  Exclusion Criteria:  having received nebulised mucoactive treatment during the previous year frequent haemoptysis (≥ 2 times/month) diagnosis or suspicion of cystic fibrosis by genetic study or sweat test being under active treatment for nontuberculous mycobacteria (NTM)