When referring to headphones, the term open air means that the headphone remains open to the outside. Open air headphones are usually more comfortable than their closed air counterparts, but they do allow sound to leak in both directions. This means that sounds from the outside can get it, potentially making it difficult to hear the headphone signal, which is of particular concern with drummers or anyone who is monitoring near loud sound sources. They also allow sound to escape to the outside, which can become an issue in recording sessions. For example, a singer’s headphone mix may leak into the vocal mic enough that it can be audible in the final recording, or at least to the extent that it effects the tonality of the final mix. For these and other reasons, closed air headphones are often used in recording situations; however, open air headphones are often preferred for general listening and/or audiophile listening applications.