Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
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It was studied a total of 45 healthy voluntary adults aged in between 18 and 40 and with equal or inferior auditory thresholds to 15 dB HL.

For their initial auditory state valuation, we carried out an otoscopic study before the conventional tonal audiometry, impedanciometry and brainstem auditory evoked potentials (BAEP) with click in 100 dB p.e. SPL. We also accomplished a BAEP study with logon stimulus of 500, 1.000, 2.000 and 4.000 Hz at 100, 80, 60 and 40 dB p.e. SPL.

In the same way, and before the stimulation with logon, we was studied the threshold identification for each stimuli logon frequencies with each one of the patients. This is in order to make sure that the smallest stimulus corresponded or matched a stimulus located above the threshold, as we were working with intensities shown in dB p.e. SPL, and therefore it was necessary the audiometric validation of the same ones regarding the dB HL used in conventional audiometry.

This stimulus is provided by AMPLAID MK15 equipment and it has a fixed number of cycles, without caring much its frequency. Due to its physical features, delta time and delta frequency, it guarantees a constant band of frequencies in octaves for the different frequencies of the test(figure 1).

Fig. 1: Logon stimuli used. Morphology, duration and frequency graphic.

varying in duration depending on the frequency. The measuring of these stimuli was performed in dB p.e. SPL (peak equivalent sound pressure level).

The data processing of the biological sign was carried out through a preamplifier and amplifier (belonging to the same equipment) and it was studied by the audio-otology software version (Table 1).

 Table 1. Parameters of Test recording with logon stimulus. 
	 Rate: 13 /sec. 
	 Window: 15 msec. 
	 Sensibility: 2,5 mV 
	 Polarity: Alternating 
	 Intensity: 100, 80, 60 and 40 dB p.e. SPL 
	 Averaging: 2.000 recordings 
	 Filters: 200-2500 Hz.

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