Int. Adv. Otol. 2011; 7:(2) 185-193

Frequency Discrimination: Frequency Modulated Difference Limen or Auditory Steady State Response?
Takwa A. Gabr, Enaas A. Kolkaila
Department of Otolaryngology–Head and Neck Surgery, Tanta University Hospitals, Tanta University School of Medicine, El-Geesh street, Tanta, Egypt.

Objective: FFrequency discrimination is a fundamental auditory process underlying more complex auditory tasks. Subjective methods are usually used to measure frequency discrimination. This research was designed to study frequency discrimination in normal hearing subjects and those with sensorineural hearing loss.

Materials and Methods: This research included two groups: control group (GI) which is composed of 30 normal hearing adults. The other is the study group (GII) which included 33 subjects with sensorineural hearing loss. Frequency discrimination was assessed using two different procedures: 80Hz-Auditory steady state response and Frequency Modulated Difference Limen.

Results: Auditory steady state response amplitude showed no significant difference between different frequencies in both groups. However, Frequency Modulated Difference Limen test showed gradual increase in the frequency difference required for discrimination as a function of increasing carrier frequency in both groups.

Conclusion: Although Auditory steady state response had been suggested as a new tool for assessing frequency discrimination, the psychophysical method such as Frequency Modulated Difference Limen still has a major role for such purpose.