Childhood wheezing is a common condition associated with asthma, but the term is often misapplied. The present study aimed to investigate the prognostic values of specific respiratory sounds for asthma onset in adolescence. In a prospective study, six specific respiratory sounds were evaluated for their prediction of asthma. Parents were asked for respiratory sounds of their initially asthma-free children and to describe them in specified terms. Self-reported doctor-diagnosed asthma of 1,569 children aged 5 to 14 years from Germany was assessed at baseline and at follow-up for up to 12 years later. Except for 'ronchus' (17%), reported 'gasp' and 'whimper' had the highest positive predictive values of 15% and 11%, respectively. These sounds also showed the greatest increase in asthma incidence (odds ratio = 3.18; 95%CI, 1.46-6.94 and odds ratio = 2.09; 95%CI, 1.00-4.37). It could be shown that from six respiratory sounds, 'gasp' and 'whimper' were the expressions with the best prediction for asthma onset. This study suggests that parents can sensibly distinguish between respiratory sounds and that it is important to specify breathing sounds, as not all are good predictors for asthma.