Can sound be "blurry?"

Can sound be considered "blurry?"

I have heard of visual things being "blurry." Examples of this include blurry photographs or blurred vision.

Is the word "blurry" restricted only to vision? I have a friend who uses the word to refer to indistinct sound. For some reason, this annoys me at an instinctual level. It seems to me that the word to use in such cases would be "muffled."

Popular usage seems to restrict the usage of "blurry" to vision.

I have a bet riding on this.

Also, are there any literary or journalistic uses of this?

In the future, you would do well to clarify the bet such that it can be objectively decided who wins. It may be a bit tricky with regards to something like "blurry sound" but here is a relevant NGram:

Blurry is used; fuzzy is used a lot more. For comparison, here is "muffled sound" vs "fuzzy sound":

The usage of blurry sound in published materials up to 2000 are ridiculously small compared to muffled sound. Post-2000 we can take a look at the straight up Google results which reveal around 9.8k results.

So people certainly use it. But the final blow comes from my local dictionary:

blur - a thing that cannot be seen or heard clearly

It explicitly mentions hearing and their example usage is "the words were a blur."

The word blurry has already been extended beyond the visual domain. One can have a "blurry memory", for example. In this sense, the word blurry simply means "vague" or "indistinct".

If your friend then takes this sense of the word and applies it to a sound, it would mean an indistinct sound. There are probably stylistically better words to use in this situation, but I think you would be hard-pressed to argue that it is actually incorrect.

As a side note, we also have terms like "loud shirt" to refer to someone wearing excessively bright colors. So bringing the adjective for one perceptual medium into another perceptual medium is something we do from time to time.

Other examples: noise (in the field of electronics), sharp (referring to taste, sound or image, even though it is a tactile adjective), bright and dark sounds (in music), smooth jazz and hard rock, white noise.