Question about Fossil Carlyle

With Android, you can easily connect a Bluetooth headset or a loudspeaker. To be honest, I have never used the watch as a loudspeaker for the smartphone, it would be kind of pointless, the loudspeaker from the phone is certainly better. When making a phone call, you can decide in my phone app (Huawei phone) which device should be used for the sound (headset, watch, phone or handsfree).
I often use a headset to listen to podcasts and the watch as a remote control to start and stop, which works fine.
I have no idea about Iphone.