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Breathing disturbances during snoring have been quantified by face mask pneumotachography and oesophageal catheters. In order to nonobtrusively investigate respiratory mechanics during nonapnoeic snoring in relation to sleep disturbances, we employed calibrated respiratory inductive plethysmography (RIP). In 10 snorers, RIP recordings were studied during nonapnoeic snoring without arousals in non-rapid eye movement (NREM) sleep, nonapnoeic snoring with repe- titive arousals in NREM sleep and wakefulness. Results were compared to RIP recordings in undisturbed NREM sleep and wakefulness in seven healthy non- snorers. Compared to wakefulness and undisturbed NREM sleep in nonsnorers, snoring was associated with predominant thoracic breathing, ribcage/abdominal asynchrony, and increased fractional inspiratory time. Preceding arousals during snoring, inspi- ratory flattening of time-derivatives of RIP volume signals, and marked ribcage/abdom- inal asynchrony indicated pronounced flow limitation. Low variation coefficients of respiratory cycle time (<10%) and tidal volume (<20%) discriminated snoring periods without arousals from snoring periods with arousals and from wakeful- ness periods, with a sensitivity of 100% and a specificity of 99%. Snoring periods with arousals were identified by the presence of snoring combined with high coef- ficients of variation of cycle time (≥10%) and tidal volume (≥20%), with a sensi- tivity of 96% and a specificity of 100%. Thus, characteristic patterns of ribcage/abdominal motion recorded by respira- tory inductive plethysmography differentiated breathing in sleep disruptive snor- ing from simple snoring. Eur Respir J 1997; 10: 576-586.