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Background information

The LISN & Learn auditory training software (Cameron & Dillon, 2007a) produces a three-dimensional auditory environment under headphones on the user's home computer. The software was designed to train children who are experiencing listening difficulties in the classroom, due to spatial processing disorder, to suppress background noise and attend to target acoustic stimuli. The software consists of four games - Listening House, Listening Ladder, Answer Alley and Goal Game. The games are played on the child's home computer. Output levels are controlled by the software and presented over headphones via an external USB soundcard.

The child's task is to identify a word from a target sentence - initially presented at 62 dB SPL and coming from 0° azimuth. The target sentence is presented in background noise - presented at 55 dB SPL and coming from + and - 90° azimuth. The background noise is looped children's stories spoken by the same female speaker as the target sentences. The child uses his or her computer mouse to select an image which is displayed on the computer screen after the sentence is presented that best matches one of the words in the target sentence.

The LISN & Learn auditory training software.

A weighted up-down adaptive procedure is used to adjust the signal level of the target based on participant's response. The target is decreased by 1.5 dB when the child correctly identifies a target image. It is increased by 2.5 dB if the wrong target identified, and it is increased by 1.5 dB if an "unsure" response is made. Each target sentence is generated from a random combination of 1,944 individual words edited from 324 recorded (and spatialized) sentences. There are 131,220 potential unique sentences that can be generated. The child plays two games per day, five days per week, over a 12 week period. Each game takes between 5 to 10 minutes to complete (Cameron & Dillon, 2008b; in press).

Nine children aged 6 to 11 years whose speech reception thresholds (SRTs) were outside normal limits on the Listening in Spatialized Noise – Sentences Test (LISN-S;  Cameron & Dillon 2009), trained on the LiSN & Learn for 15 minutes per day for 12 weeks. All nine children performed within normal limits on the LiSN-S post-training. For eight of the nine children these results were maintained three months after the training was completed. Group statistics revealed that post-training, participants showed a significant improvement in SRT on the three conditions of the LiSN-S where the target is spatially separated from the distracters (p ranging from 0.001 to 0.0002). There was no significant improvement in SRT on the LiSN-S conditions where the target and distracters emanate from the same location (p ranging from 0.158 to 0.981). Speech reception threshold (SRT) on the LiSN & Learn improved by approximately 8 dB over the course of the training across participants. Statistical tests revealed a significant improvement between SRT averaged over the first 30 days of training compared with the final 30 days of training (p = 0.000052). On a self-reported questionnaire on spatial hearing ability, listeners ratings of hearing in background noise (scaled from very easy to very hard) improved significantly post training (p = 0.0002), whereas ratings listening in quiet did not change significantly (0.103). Significant post-training improvements were also found on measures of memory and attention. It was concluded that the training strengthens or reorganises connections dedicated to binaural processing, enhancing the participants' ability to process speech in background noise.

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References:

1. Cameron S, Dillon H. (in press) Development and evaluation of the LiSN & Learn Auditory Training Software for deficit-specific remediation of binaural processing deficits in children: preliminary findings. Journal of the American Academy of Audiology. (Accepted 29 April 2011).

2. Cameron S, Dillon H. (2009) Listening in Spatialized Noise – Sentences test (LiSN-S) (Version 1.013) [Computer software]. Murten, Switzerland: Phonak Communications AG.

3. Cameron S and Dillon H (2008a). Spatial hearing deficits as a major cause of auditory processing disorders: Diagnosis with the LiSN-S and management options. In R. Seewald & J. Bamford, eds. A Sound Foundation Through Early Amplification 2007. Proceedings of the Fourth International Conference: Phonak AG, Switzerland, pp 235-241.

4.Cameron S and Dillon H (2007a). LiSN & Learn Auditory Training Software (Research Version 1.1.0) [Computer software]. Sydney, NSW: National Acoustic Laboratories.

5.Cameron S and Dillon H (2007b). The Listening in Spatialized Noise - Sentences Test (LiSN-S): Test-retest reliability study. International Journal of Audiology, 46:145-153.