[Normal parameters of ear acoustic emissions in neonates].
BACKGROUND
The ear acoustic emissions (EAE) are produced from pure low intensity tones coming from the cochlea in response to a stimulus. Hypocusia in the neonate may be detected by universal hearing screening programs using EAE that have a sensitivity of 91% and specificity of 85%.


OBJECTIVE
To define the normal limits we measured the EAE in a group of healthy newborns and calculated the media and standard deviation (SD).


METHODS
We enrolled 280 healthy neonates, previous external ear evaluation for permeability and we measured the EAE at 7 to 30 days of life at 2000, 2500, 3187, 4000, 5062 y 6375 Hz, using a 55-65 dB stimulus for each frequency band.


RESULTS
In each frequency band evaluated we calculated the media: 10.76, 9.16, 9.46, 7.89, 4.83, 2 dB SPL, and minus two SD: 0.54, -0.33, 0.06, -2.04, -4.37, -7.43 dB SPL, that we considered the lower limit of normality for both ears in each frequency band tested. There were no significant differences between measurements in both ears (p>0.05).


CONCLUSIONS
The EAE measurement is an easy, and low cost test that can be used to make the universal hearing screening accessible. These results support the normal levels of EAE and the Corti organ function in healthy newborns.
Hernández-Herrera
Ricardo Jorge
RJ
Departamento de Pediatría, Hospital Regional de Especialidades 23, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, Mexico. richdzher@hotmail.com
Hernández-Aguirre
Luz María
LM
Castillo-Martínez
Norma
N
de la Rosa-Mireles
Natalia
N
Martínez-Elizondo
Jesús
J
Flores-Santos
Roberto
R
Torcida-González
Miguel Eloy
ME
Hernández-Núñez
Rogelio
R
D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D012016:Reference Values