re: lost voice
Depends on the company - the bigger they are, the more rigidly they adhere to policies that really need a bit of leeway and common sense.
Phone in for sickness - lost voice and I worked phones in a call centre so without a voice, couldn't work. Mum phoned in for me. They insisted on speaking to me directly, even though all I could do was faintly squeak.
Notice in writing (not email) if absence is longer than 3 days. My friend's hand was crushed. His notice was then rejected because his (left-handed) signature on the letter was nothing like his usual (right-handed) signature. That was local govt.
The winner was the Dept of Work and Pensions. A friend was in a car crash and broke her spine. Had to spend 6 weeks flat on her back. DWP said she had to come in to their offices for an assessment. When she said she couldn't come in because she couldn't even sit upright in a taxi, they stopped her sick pay because she had "refused" to comply.