This detailed book edited by Hirschberg, Szende, Koltai, and Illényi presents the results of 45 years of work in the subjective and objective analysis of the pathologic respiratory sounds made by 370 infants and young children. The children were referred to 3 hospitals in Budapest for evaluation of pathologic sound phenomena of respiratory origin. All sounds were preverbal, nonspeech sounds. The case selections were based on the authors' examination of nearly 3000 infants with pathologic sound phenomena. There is no discussion, however, as to how and why the case children were selected for acoustic analysis from this group of 3000 individuals; likewise, there is no discussion if they were selected because they were deemed representative of their condition or whether there was a more random reason for selection, thereby reducing a potential selection bias. The authors have taken care to include a control group of 50 healthy infants but do not indicate how they were selected.
Frosh A. Pediatric Airway: Cry, Stridor, and Cough. JAMA. 2009;301(22):2391-2394. doi:10.1001/jama.2009.824