Does feedback matter in an auditory frequency discrimination learning task?

While it is well known that an auditory training of normal-hearing adults can result in significant learning gains, less in known about the influence of feedback on such gains. The objectives of the present study were: (1) to investigate the influence of feedback on the performance of a frequency discrimination task; (2) to compare the learning-dependent gains between different feedback training protocols, and (3) to evaluate the influence of background noise on the efficiency of the auditory learning. Two groups of normal-hearing subjects participated in a single-session training. The session comprised of nine difference limen frequency (DLF) thresholds for 1 kHz in background noise using a three-interval, two-alternative forced choice paradigm (n = 17). One group of eight participants ('feedback-first' group) was trained using visual feedback in the first three thresholds estimations followed by three estimations with no feedback and then by another three estimations with feedback. For the second group of nine participants ('feedback-later' group), feedback was provided in the reversed order. Additional two DLF measurements were performed with feedback in both groups in quiet. Our results show that: 1) auditory learning of a frequency discrimination task using an adaptive procedure can occur whether feedback is provided or not; 2) changing the strategy of feedback in the middle of the training session discontinued the effect of training; and 3) the protocol of feedback by which listeners started with, seemed to determine their strategy of learning. The results support the notion that the adult learning mechanism may be limited by the initial strategy of learning to which it is introduced. Nevertheless, similar gains in performance can be obtained, regardless of the provision of the strategy adopted by the listener.