What is the term for the quietest level a patient can hear a tone presented approximately 50% of the time?

The term for the quietest level a patient can hear a tone presented approximately 50% of the time is referred to as the threshold. In audiometric testing, the threshold is determined by presenting a tone at various intensities and identifying the lowest level where the patient can reliably detect the sound. This measurement is crucial as it helps audiologists assess hearing ability and design appropriate treatment plans.

Understanding the threshold is also important in differentiating it from other terms. Interaural attenuation refers to the loss of intensity of a sound as it travels between the ears, which is relevant in binaural hearing tests but does not define a patient's hearing sensitivity directly. The occlusion effect describes the increase in loudness that occurs when the ear canal is occluded, an aspect relevant to fitting hearing aids but not to identifying hearing sensitivity. Lastly, an octave is a term used in music and acoustics to denote a doubling or halving of frequency but does not relate to the assessment of hearing thresholds. Thus, recognizing threshold is fundamental in audiometry and hearing aid fitting practices.