Although Cisco Systems performs limited internal testing of third-party headsets for use with the Cisco Unified IP Phones, Cisco does not certify or support products from headset (or handset) vendors.
Cisco recommends the use of good quality headsets that are screened against unwanted radio frequency (RF) and audio frequency (AF) signals. Depending on the quality of the headsets and their proximity to other devices such as mobile phones and two-way radios, some audio noise or echo may still occur. An audible hum or buzz may be heard by either the remote party or by both the remote party and the Cisco Unified IP Phone user. Humming or buzzing sounds can be caused by a range of outside sources: for example, electric lights, electric motors, or large PC monitors.
In some cases, hum may be reduced or eliminated by using a local power cube or power injector.
These environmental and hardware inconsistencies in the locations where Cisco Unified IP Phones are deployed means that there is not a single headset solution that is optimal for all environments.
Cisco recommends that customers test headsets in their intended environment to determine performance before making a purchasing decision and deploying on a large scale.
Beyond physical, mechanical, and technical performance, the audio portion of a headset must sound good to the user and to the party on the far end. Sound quality is subjective and Cisco cannot guarantee the performance of any headsets. However, a variety of headsets from leading headset manufacturers are reported to perform well with Cisco Unified IP Phones. For details, see the headset documentation.