thurrott[.]com/mobile/android/198901/google-brings-new-accessibility-apps-to-android
Live Transcribe works like the live captioning you see on TV, but is interactive: It translates live speech to on-screen text in over 70 languages and dialects...Sound Amplifier works with wired headphones to filter, augment and amplify the sounds in your environment. It pumps up the volume of quiet sounds while not over-boosting loud sounds.
The amplifier app has been done before -- AFAIK this is the 1st attempt by Google, which may or may not work better, I imagine based on the hardware used & the type & degree of hearing impairment of the person using it.