I have a relatively specific thought on acoustic masking, and wanted to know what others think, or if folks know of studies that have addressed this problem.
When studying acoustic masking, we often think about the frequency range of a signal of interest, say for example high frequency whistles of odontocetes, and then examine the overlap of a competing signal that might be causing masking, say for example boat noise. In scenarios where there is strong overlap between the two signals, for example, the whistle at 5 kHz and the boat noise in the 10 Hz to 10 kHz range, and the noise source has higher amplitude than the signal of interest, we would say that there is a high level of acoustic masking.
However, now imagine a scenario where the noise source is in a different frequency range. For example, the odontocete whistle is at 15 kHz, but the noise source is in the 10 Hz to 10 kHz range. If we viewed the two signals on a spectrogram, both sources would be clearly visible. Definitions of masking that I'm aware of would suggest that masking is not occurring. However, what if the noise source had sufficiently high amplitude such that it was still difficult for the receiver to hear the whistle? At some high amplitude, a temporary threshold shift would occur, along with effectively "clipping" of the receiver's hearing system. But how well can animals hear around high amplitude sounds, effectively using a bandwidth filter to only focus on the signals of interest while ignoring adjacent high amplitude sounds? Is there some quantifiable cutoff below the level for hearing damage?