We present measurements of the damping experienced by custom-made quartz tuning forks submerged in ³He covering frequencies from 20 kHz to 600 kHz. Measurements were conducted in the bulk of normal liquid ³He at temperatures from 1.5 K down to 12 mK and in superfluid ³He-B well below the critical temperature. The presented results complement earlier work on tuning fork damping in ³He, removing possible ambiguities associated with acoustic emission within partially enclosed volumes and extend the probed range of frequencies, leading to a clearly established frequency dependence of the acoustic losses. Our results validate existing models of damping and point toward the same mechanism of wave emission of first sound in normal ³He and liquid ⁴He and zero sound in superfluid ³He. We observe a steep frequency dependence of the damping ≈ f^5.5, which starts to dominate around 100 kHz and restricts the use of tuning forks as efficient sensors in quantum fluids. The acoustic emission model can predict the limiting frequencies for various devices, including micro-electromechanical and nano-electromechanical structures developed for quantum turbulence and single vortex dynamics research.