Background <p>This study aimed to present normative data on extended high-frequency (EHF) thresholds in healthy adults.</p> Methods <p>This observational study included 200 individuals (400 ears) with normal hearing based on the four frequency pure-tone average. Participants ranged in age from 18 to 70 years and were divided into five age groups. Each group consisted of 40 participants (80 ears), with an equal number of males and females. The preliminary assessments involved acoustic immittance tests, otoacoustic emission evaluation, pure-tone audiometry, and speech audiometry. Subsequently, EHF audiometry was performed to assess EHF thresholds within and between groups based on ear side (right vs. left), gender, and age.</p> Results <p>The study found no statistically significant difference in EHF thresholds between the right and left ears across all groups (<i>p</i> &gt; 0.05). However, when the effect of gender was analyzed, a statistically significant difference in EHF thresholds was observed in the 30–39, 40–49, and 60–70 age groups (<i>p</i> &lt; 0.05). A statistically significant difference was also found between the groups for each EHF (<i>p</i> &lt; 0.05). EHF thresholds were observed to increase with age. The frequency most strongly correlated with age was 12.5&#xa0;kHz (<i>r</i> = 0.828, <i>p</i> &lt; 0.001).</p> Conclusions <p>This study has demonstrated the effects of gender and age on EHF thresholds. The normative data presented in this study may contribute to the early detection, prevention and treatment of pathologies affecting the EHF thresholds.</p>