I’m wondering if there is something I can use to alert me of a phone call on my mobile at night when my hearing aids are out.
Yes. It would be a good idea to contact the phone manufacturer to see what they have available. Some tech companies have developed discreet, modern bracelets and smartwatches that alert people when their mobile phone is ringing.
Some other systems are also used as alert systems for mobile phones, e.g. the Bellman Pro alarm clock with mobile phone sensor.