Relationship Between Distortion Product - Otoacoustic Emissions (DPOAEs) and High-Frequency Acoustic Immittance Measures.
BACKGROUND Pathologies that alter the impedance of the middle ear may consequently modify the DPOAE amplitude. The aim of this study was to correlate information from 2 different clinical procedures assessing middle ear status. Data from DPOAE responses (both DP-Gram and DP I/O functions) were correlated with data from multi-component tympanometry at 1000 Hz. MATERIAL AND METHODS The subjects were divided into a double-peak group (DPG) and a single-peak group (SPG) depending on 1000 Hz tympanogram pattern. Exclusion criteria (described in the Methods section) were applied to both groups and finally only 31 ears were assigned to each group. The subjects were also assessed with traditional tympanometry and behavioral audiometry. RESULTS Compared to the single-peak group, in terms of the 226 Hz tympanometry data, subjects in the DPG group presented: (i) higher values of ear canal volume; (ii) higher peak pressure, and (iii) significantly higher values of acoustic admittance. DPOAE amplitudes were lower in the DPG group only at 6006 Hz, but the difference in amplitude between the DPG and SPG groups decreased as the frequency increased. Statistical differences were observed only at 1001 Hz and a borderline difference at 1501 Hz. In terms of DPOAE I/O functions, significant differences were observed only in 4 of the 50 tested points. CONCLUSIONS The 1000-Hz tympanometric pattern significantly affects the structure of DPOAE responses only at 1001 Hz. In this context, changes in the properties of the middle ear (as detected by the 1000 Hz tympanometry) can be considered as prime candidates for the observed variability in the DP-grams and the DP I/O functions.
Department of Physical Therapy, Speech Therapy and Occupational Therapy, University of São Paulo of Medicine, São Paulo, SP, Brazil.
Ualace De Paula
Ude P
Campos
Audiology and ENT Department, University of Ferrara, Ferrara, Italy.
Stavros
S
Hatzopoulos
, Institute of Physiology and Pathology of Hearing, Warsaw, Poland.
Lech K
LK
Śliwa
Department of Heart Failure and Cardiac Rehabilitation, Medical University of Warsaw, Warsaw, Poland.
Piotr H
PH
Skarżyński
, Institute of Physiology and Pathology of Hearing, Warsaw, Poland.
Wiesław W
WW
Jędrzejczak
, Institute of Physiology and Pathology of Hearing, Warsaw, Poland.
Henryk
H
Skarżyński
Department of Physical, Therapy Speech Therapy and Occupational Therapy, University of São Paulo of Medicine, São Paulo, SP, Brazil.
Renata Mota Mamede
RM
Carvallo
D000158:Acoustic Impedance Tests / Q000379:methods*; D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001299:Audiometry / Q000379:methods; D001309:Auditory Threshold / Q000502:physiology; D004432:Ear, Middle / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D055815:Young Adult