Low resolution

High resolution

The combined F&T test of Larsby and Arlinger is used for investigating auditory resolution in the frequency and the temporal domain. The F&T test is an advanced test, which will only be performed when the need arises during the diagnostic session.

The F&T test can be used to measure spectral, temporal, and combined spectro-temporal resolution. Masked thresholds of tone pulses in four different noises are measured using a Békésy tracking technique. Noises are continuous octave-band noise, noise with spectral gaps, noise with temporal gaps and noise with both spectral and temporal gaps. Release of masking values (calculated as the difference in hearing thresholds between the condition with maximum masking and the condition with spectral and/or temporal gaps) are used as measures of spectral, temporal and spectro-temporal resolution.

The signal is a pulsed tone (2.22 pulses/sec) with a frequency of 0.5 and 3 kHz, long enough to maintain the tonal character of the stimulus. Noise masks are octave-band noises around the signal frequencies, with or without spectral gaps (0.5-octave wide gaps around the signal frequency) and temporal gaps (10-ms silent periods symmetrically placed around the centre of the test tone). The noise level is fixed and the tone level changes according to the tracking method at a rate of 3 dB/sec.

Subjects are instructed to press a button or space bar when the tone is audible, leading to a decreasing tone level, and to release the button when the tone becomes inaudible, leading to an increasing tone level. The result is derived from the levels used in the up-down procedure for the last six reversals.

Information about the software version of the test.

Larsby B, Arlinger S (1998) A method for evaluating temporal, spectral and combined temporal-spectral resolution of hearing. Scandinavian audiology 27(1):3-12

Further test procedures in the Auditory Profile.