In an example embodiment, a system that appropriately routes calls to an agent at a contact center based on the agent's voice and/or hearing characteristics. The agent is selected by matching speech and hearing characteristics of a caller with the speech and hearing characteristics of an agent. In order to find the best match for the caller, the contact center determines if the caller is hearing impaired, and if so determines a suitable frequency range for the caller. If a match cannot be found, the agent's and/or caller's voice may be shifted in real time and adjusted to a frequency range that is best suited for the caller.