It depends on the specific model of Bluetooth speaker you are using. Some Bluetooth speakers come with built-in microphones that allow for hands-free calling, while others do not. If you are interested in using a Bluetooth speaker for hands-free calling, you should check the product specifications or documentation to see if it has a built-in microphone. Alternatively, you can look for Bluetooth speakers that are specifically marketed as being suitable for hands-free calling, as these are more likely to have a built-in microphone.