2007 Toyota bluetooth loudspeaker problem

With my windows up, pulled into a parking lot talking on my phone with bluetooth (Verizon-Droid). A colleague found me when I got into the building, saying that she’d heard my whole conversation outside my car! She said it sounded like I was using a loudspeaker outside the car! (Luckily it wasn’t a confidential conversation) When we got inside, other colleagues heard us still talking about it. Turns out that this is happening to another woman with a 2007 Camry. Is this a dealer problem? Or a setting I can fix? Nothing about it in the manual. Help!