Abstract
The amplitude of the 2f1–f2 distortion product otoacoustic emission (DPOAE) can be suppressed by presenting contralateral acoustic stimulation. To test the hypothesis that DPOAE contralateral suppression is influenced by the primary frequency in DPgrams, DPgrams were recorded at resolutions of 1, 8, and 17 pts/octave, in the absence and presence of contralateral broadband noise (BBN). Participants were 20 normal-hearing human adults. In DPgrams with higher frequency resolutions, DPOAE suppression at amplitude peaks in DPgrams (8 pts/octave: Mean = − 0.92 dB, SD = 0.71 for BBN at 60 dB SPL; 17 pts/octave: Mean = − 0.25 to −1.44 dB, SD = 0.51 to 0.86 for BBN at 40 to 70 dB SPL, respectively) was larger than the suppression at the dips in DPgrams (8 pts/octave: Mean = − 0.13 dB, SD = 1.00; 17 pts/octave: Mean = − 0.03 to −0.73 dB, SD = 0.55 to 0.91). A larger intersubject variability in DPOAE contralateral suppression was observed at the dips. The results suggest that measuring DPOAE contralateral suppression at the primary frequencies corresponding to the peaks in DPgrams with higher frequency resolutions may improve the assessment of the efferent system function.
Abbreviations | ||
A | = | Audiometric frequencies |
ANOVA | = | Analysis of variance |
BBN | = | Broadband noise |
D | = | Dip points |
DPOAEs | = | Distortion product otoacoustic emissions |
LOC | = | Lateral olivocochlear efferent system |
M | = | Intermediate points |
MOC | = | Medial olivocochlear efferent system |
OHC | = | Outer hair cells |
P | = | Peak points |
SD | = | Standard deviation |
SOAEs | = | Spontaneous otoacoustic emissions |
TEOAEs | = | Transient evoked otoacoustic emissions |
Abbreviations | ||
A | = | Audiometric frequencies |
ANOVA | = | Analysis of variance |
BBN | = | Broadband noise |
D | = | Dip points |
DPOAEs | = | Distortion product otoacoustic emissions |
LOC | = | Lateral olivocochlear efferent system |
M | = | Intermediate points |
MOC | = | Medial olivocochlear efferent system |
OHC | = | Outer hair cells |
P | = | Peak points |
SD | = | Standard deviation |
SOAEs | = | Spontaneous otoacoustic emissions |
TEOAEs | = | Transient evoked otoacoustic emissions |
Sumario
La amplitud de la emisión otoacústica 2f1–f2 (DPOAE) puede ser suprimida por la presentación de una estimulación acústica contralateral. Para evaluar la hipótesis de que la supresión contralateral de las DPOAE está influenciada por la frecuencia primaria en los DPgramas, se registraron DPgramas con resoluciones de 1, 8 y 17 puntos/octava, en ausencia y presencia de un ruido contralateral de banda ancha (BBN). Los participantes fueron 20 humanos adultos con audición normal. En los DPgramas con mayor resolución de frecuencia, la supresión de las DPOAE en amplitudes pico del DPgrama (8 pts/octava; Media = − 0.92 dB, DS = 0.71 para BBN a 60 dB SPL; 17 pts/octava: Media = − 0.25 a −1.44 dB, DS = 0.51 a 0.86 para BBN a 40 − 70 dB SPL, respectivamente) fue mayor que la supresión en las caídas del DPgrama (8 pts/octava; Media = 0.13 dB, DS = 1.00; 17 pts/octava: Media = − 0.03 a −0.73 dB, DS = 0.55 a 0.91). Se observó una variabilidad mayor entre sujetos en la supresión contralateral de las DPOAE en las caídas. Los resultados sugieren que la medición de la supresión contralateral de las DPOAE en las frecuencias primarias que corresponden a los picos del DPgrama con mayor resolución de frecuencia, pueden mejorar la evaluación de la función del sistema eferente.