Begins to say less in phone conversations
When it happens Mild-stage dementia
Why it happens Tracking a conversation grows harder as concentration falters. Phone conversations are especially challenging because, without being able to "read" facial expressions, interpreting the words is more difficult. It also becomes progressively harder to remember what was said at the beginning of a conversation and then respond appropriately when it's your turn; silence is simpler. Hearing two or more disembodied voices on the line at once can be especially confusing.
What you can do
You don't have to stop calling. The person may still welcome hearing your voice.
Identify yourself: "Hi Mom, it's me, your daughter Sally."
Don't take it personally if the person responds with irritation; it's not you, it's the situation.
Don't goad the person into talking.
Consider supplementing calls with written messages.