The TNT is a reliable and efficient clinical test that allows measurement of a hearing-impaired listener’s tolerance for noise — with and without hearing aids — so that the results can be compared to normal-hearing listeners, among various hearing aid features, and on the same individual over time. This tool may also be useful for estimating potential satisfaction of the fitted hearing aids in real-life noisy environments.
The TNT test is a computerized, automatic test that simplifies the process of measuring “tolerable” noise while ensuring the reliability of the measured results. The test does not require the measurement of individual MCLs; rather, based on ecological consideration, a fixed speech passage at 75 or 85 dB SPL is used to approximate the speech level in loud background noise. The purpose of the test is to track the listener’s tolerable noise level (TNL)—defined as the loudest noise level that the listener is able and willing to “put up with” without sacrificing speech understanding—over a 2-minute period. The test has within-session, test-retest reliability of 2 dB and a between-session reliability of 4 dB.