British journal of audiology
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Thirty patients undergoing open heart surgery under induced hypothermia had transient evoked otoacoustic emissions (TEOAE) recorded during cooling to 26.07 degrees C (standard deviation (SD) 4.25 degrees C) vesically measured temperature and 24.86 degrees C (SD 4.7 degrees C) nasopharyngeally measured temperature respectively. Subsequently tè patients were rewarmed until normal body temperature was reached again. There was a clear influence of body temperature on the amplitudes and reproducibilities of the TEOAE. ⋯ No TEOAE were measurable during cooling at a mean temperature lower than 33.41 degrees C (SD 2.04 degrees C) vesical temperature and 30.16 degrees C (SD 3.0 degrees C) nasopharyngeal temperature respectively. During rewarming the echoes became recognizable again at a mean temperature of 28.75 degrees C (SD 3.38 degrees C) vesical temperature and 27.49 degrees C (SD 2.99 degrees C) nasopharyngeal temperature. These results suggest a hysteresis in the relationship between the amplitude of TEOAE and temperature, similar to the well-established relationship between evoked potentials and temperature.