Bat detector for the deaf / hard of hearing

I have a bat detector that gives an audio output that can be recorded. I would like to be able to convert the signal to a visual representation so that deaf people can appreciate the experience. I am a complete novice however I thought it should be possible to pass it through the raspberry pie and get the the GPIO pins to flash a simple LED array (Such as found in a head torch?) I am aware that there are a number of hats available but they are too expensive for this project as I will be giving the finished units away foc.
Any help would be appreciated as I am a complete novice when it comes to writing code

essentially you want to turn an audio signal into a EQ representation or similar?

I know of one project that specifically aims at ‘turning sounds into light’:

whether it’s appropriate to your purpose I’m not sure but it sounds like it could be?

I have spoke to an electronics specialist and it seems as though I am using a sledge hammer to crack a nut. he is going to set up a simple (and cheap) amplifier to power a few LED’s instead of a speaker and that will do the trick. However the lightshow pi could be useful for a more advanced version that could indicate different species of bats as they all use different frequencies