TEST PROCEDURE OF ABLB TEST(AlternateBinaural Loudness Balance test):-
step1:- The hearing threshold level by air conductionfor the frequency at which the test is being done is ascertain in both ear.
Step2:- The attenuator dial for the wrose (deafer)ear is set at 20dB SL and for the better ear at 0dBSL.
Step3:-the ABLB function is started in the audiometer , such that, the tones alternate between the two ears and the patient is asked to indicate in which ear the sound appear louder. if the tone in the poor ear appears louder than that in better ear, then step 5th is started.
Step4:- Tone in the better ear is raised by 5dB .
Step5:-Tone in the better ear is lowered by 5dB.
Step6:-Patient is asked whether loudness is equal on both ears.If equal , then this level of tone in the better ear is recorder as equal in loudness to 20dB SL in the poor ear.
If not equal then, patient is asked again in which ear the tone is louder. if poor ear is louder then tone in tone in better ear is raised by 5dB, and if better ear is louder then poor then tone is lowered by 5dB.
This process is repeated till the loudness of the tone is equal in the two ears and the level of the tone in the better ear is then recorder to be equal in loudness to a 20dB SL sound in the impaired ear.
This process is repeated at steps of 10dB increment for poor ear. the level of tone in the beteer ear that is equal in loudness to 30dB SL , 40dB SL, 50dB SL .... in the poor is recorder till the maximum of the audiometer is reached and the sound in the impaired ear cannot be increased any further.
