Find my iPhone Alert Sound

I have searched high and low for an answer to this question with no luck. My wife was totally deaf but received a cochlear implant in one ear about four years ago. She can understand speech very well but with only hearing in one ear it difficult to tell the direction that sound is coming from. She recently misplaced her phone and I was able to find it using the find my iPhone app. She could hear the sound but had no idea where it was coming from. I understand that it is not possible to change this alert sound. With all the enhancements (?) that Apple makes with each new iOS release it would be nice if they could give the user the option of changing this sound. Rather than the current "pinging" sound it might make it easier for her to locate some type of louder siren sound. I change choose from 100's of emojis but can't change the alert sound when my phone is lost?