A frequency of 12 kHz is a component of most modem audiometers, but the traditional routine audiogram does not surpass the 8-kHz frequency. In the present study 12 kHz frequency was included in the routine audiogram. The 12 kHz thresholds in different audiologic entities are described. The most prominent finding justifying the utility of 12 kHz frequency was the correlation between complaint of subjective tinnitus and 12 kHz as a single-frequency hearing loss. This correlation has important medicolegal implications. Another finding was the 12 kHz high sensitivity of patients suffering from chronic otitis media. In conclusion, where possible, 12 kHz frequency should be an integral part of the routine audiogram. When we refer to the classical audiogram as being ''normal'', we usually relate to the air conduction at 250 to 8000 Hz. The concept of ''normal audiogram'' means only that the examinee's hearing is in the normal range for communication, while the possibility of hearing impairment above 8 kHz exists. One of the most challenging and complex areas under investigation is the link between hearing and tinnitus. This subject has even more importance in light of the medicolegal aspects. Tinnitus with ''normal'' hearing is not an extremely rare phenomenon. The electrical high-frequency audiometer enables the evaluation of hearing thresholds up to 20 kHz (1). This device is still not considered an indispensable part of every audiological institute. Nevertheless, most modern audiometers are capable of hearing evaluation for 12 kHz. Therefore, for little extra effort, the classical audiogram can be expanded to give more information on high-frequency thresholds. In 1980 Erickson et al. claimed that thresholds for frequencies above 8 kHz are not predictable from thresholds in the conventional frequency range (2). Fausti and Rappaport, in 1981 (3) and late in 1986 (4), stated that the effect of noise exposure and ototoxic agents can be recognized first at frequencies higher than 8 kHz, and only later are they evident at the lower frequencies. High-frequency sensitivity can provide an early warning of cochlear damage (5). In the AVR Audiological Institute there are audiometers capable of testing 12 kHz. Therefore, we performed expanded audiograms in different patients with hearing impairment, as well as in normal subjects, in order to better understand the significance of high frequency of 12 kHz.
