Well have you ever considered following the policy procedures for incoming call handling:

Collect all relevant facts before placing the customer on hold.
Follow all appropriate hold procedures:
Explain the reason for placing customer on hold (Set the expectation for the approximate length of time they will be placed on hold).
Obtain the customer's permission before placing them on hold (wait for response).
Examples: "Mr. Smith, may I place you on hold for a moment while I review your invoice?"
Return to the call and thank the customer for holding.
Examples: "Mr. Smith, thank you for holding. I have reviewed your invoice and."
Use your hold button instead of mute, when researching information.
Return to the customer within 90 seconds of the initial hold and/or set the expectation for additional hold time needed.
Confirm that he/she will continue to hold if additional time is required and offer the option of a return call if hold is not desired.