This has already been discussed at length in other topics (some relevant discussion in Audio recordings of bird song/calls). To sum up one of the major points: spectrograms are only a useable quality of information if a standardized scale is used. People may become accustomed to identifying spectrograms at one scale, but if someone posts a spectrogram using a scale other than the one they are used to, it becomes much harder.
There is an existing feature request (Automatically add a spectrogram view to observations with sounds) that if implemented, would produce standardized spectrograms for audio when uploaded.