Purpose: Distortion product otoacoustic emissions (DPOAEs) are a by-product of active cochlear processes that lead to the compressive nonlinearity of healthy ears. The most commonly studied emission is at the frequency 2f[subscript 1]-f[subscript 2] , but there has been recent interest in using the quadratic distortion product at the frequency f[subscript 2]-f[subscript 1] to detect cochleopathies including endolymphatic hydrops. Before the DPOAE at f[subscript 2] -f[subscript 1] can be applied clinically in any capacity, optimal stimulus parameters for its elicitation must be established. Method: We investigated stimulus parameters for the DPOAEs at f[subscript 2]-f[subscript 1] and 2f[subscript 1]-f[subscript 2] in 23 adults with normal hearing. Logarithmically swept tones between approximately 0.6 and 20 kHz (L[subscript 1] = L[subscript 2] = 70 dB SPL) served as the higher frequency stimulus (f[subscript 2]). DPOAEs were measured for 6 f[subscript 2]/f[subscript 1] ratios: 1.14, 1.18, 1.22, 1.30, 1.32, and 1.36. Results: Both DPOAEs were consistently measurable. In line with previous investigations, the highest levels of the DPOAE at 2f[subscript 1]-f[subscript 2] were generated between f[subscript 2]/f[subscript 1] ratios of 1.14-1.22, with a peak in the level ratio function at 1.22. In contrast, f[subscript 2]-f[subscript 1] was less influenced by ratio, although the narrowest ratio (1.14) produced slightly higher levels across frequency. Conclusion: The DPOAE at f[subscript 2]-f[subscript 1] is measurable in individuals with normal hearing up to f[subscript 2] of 20 kHz at narrow f[subscript 2]/f[subscript 1] ratios. Measurements at additional stimulus levels and in subjects with hearing impairment will be needed before clinical implementation.