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Initially, all individuals were tested with the sentences from list 1A (a list containing 25 sentences), used for training. The training was always presented only in one ear along with the noise recorded on the CD. The initial level for presenting the sentences was 75 dB HL, i.e. +10 signal/noise ratio.
Testing started after the training. Firstly, with the presentation of the subsequent lists, along with the noise recorded on the CD and then with the use of speech-noise noise present in the audiometer, and with the remaining lists. Different lists were always used for different noises and different ears.
It is important to mention that in the first study with earphones, at 7 dB difference between the recording volume of the two signals presented (speech and noise) was observed, and the sentences were recorded at an average intensity 7 dB below the intensity of the noise. For this reason, the author of the test indicated that, for the evaluations using earphones, it is necessary to subtract 7 dB from the speech values observed on the equipment’s dial, a procedure thus adopted in this study.
Acoustic immittance measurements were performed with the AZ7 – R - Interacoustics® middle ear function analyzer. For recording otoacoustic emissions, the Echoport ILO292 USBII, ILO V6 Clinical software, was used. The audiometry and speech recognition tests were performed in an acoustic booth with an AC33 - Interacoustics® clinical audiometer and duly calibrated Telephonics® TDH-39 earphones. The sentences were presented using the original CD of the LSP test and a Compact Disc Digital Player, coupled to the audiometer.