Abstract
This study was designed to measure auditory function in patients with chronic obstructive pulmonary diseases (COPDs) who gener-
ally suffer from chronic hypoxemia. Control and COPD subject groups received a battery of tests to assess overall hearing sensitivity and
peripheral (end-organ and eighth-nerve) and brain-stem auditory function, as well as blood-gas analysis. Results showed a statistically
significant difference for all audiological measures between the control group and a COPD subgroup – the presumptive hypoxic subjects
(partial oxygen tensions, PO 2 , <75 mm Hg). Correlation analyses of results from all subjects (regardless of PO 2 ) also revealed significant
covariance with PO 2 for overall, RMS, amplitude of click-evoked otoacoustic emissions (RA), hearing threshold level, and auditory
brain-stem response (ABR, I-V inter-peak latency). v
2
or Fishers exact tests were statistically significant for frequencies of cases classified
according to a criterion PO 2 of 70 mm Hg (putative critical O 2 for completely normal auditory function) and either hearing thresholds
falling below or RA values above 1.5 standard deviations of the control-group means, respectively. However, v
2
was not significant for a
comparable criterion of ABR I-V IPL. In general, clinically significant hearing loss was uncommon in COPD patients, and the observed
effects represented relatively small changes in the auditory measures examined. Still, overall, changes were in the direction of poorer func-
tion, and these results suggest physiologically significant impact of chronic hypoxemia and the need for further study to evaluate thor-
oughly this medical condition as a potential risk factor for audio-vestibular dysfunction.