Hello and welcome to the forum. Thanks for your question. How long have you been taking Losartan? We encourage you to check back in iwth your doctor about this to discuss. Here is a list of side effects associated with Losartan. https://www.drugs.com/sfx/losartan-side-effects.html Uncommonly, ear congestion and hearing loss occur. But you are describing hypersensitivity. Losartan is associated for some with tremor. I would wonder if the sound issue is not related to a bit of anxiety. I'm not really seeing anything in the literature to support what you describe with retards to sound being louder but sensory experiences can be affected whenever our nervous system is not regulated. Please check in with your doctor and let us know what they say.
How are things going? Have you had a chance to contact your doctor yet?