With one of our phones, the caller cannot hear the voice of the receiver (my office staff). We've tried different hand pieces, rebooted the phone, double checked all connections, yet with the hands free unit, the caller can hear the receiver (my office staff) just fine.
Did you only swap the handset or did you swap the handset and the cord as well?
If you did then I can only assume some sort of defect has occurred. I have not heard of this before and you would need to speak to your Polycom reseller.
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Polycom Global Services
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