Increase auto answer time

[Brian 4500]

My S4 allowed me to increase the length of time before my phone would answer when I have my ear phones plugged in and I am listening to music. My new S6 seems to only allow 2 seconds. Path is Phone -Settings-Auto Answer and set to on, but the default time seems to be unchangeable. How do I change it to maybe 6 or 10 seconds?