Scared I hurt baby with home DoppleršŸ™

I purchased one of these. I knew I shouldnā€™t have. it arrived I tried it and I was told i have a anterior placenta so we knew weā€™d have a really hard time finding it since my ob had a hard time locating it. Well we probably spent like 10-15 minutes searching and after doing some re search online. Apparently they do use sound waves and can hurt baby ears. So now I feel like a horrible person because Iā€™m worried I had it on my belly for too long

:( I havenā€™t used it since and told husband we wonā€™t use it at all anymore. But does anyone think itā€™s possible that I hurt my baby? Sorry if itā€™s a dumb question but this is my first pregnancy and we had to do <a href="https://glowing.com/glow-fertility-program">ivf</a> to get her so Iā€™m really paranoid. Thanks moms.