3.3. The Procedure of the Sentence Final Word Identification and Recall Test (SWIR)

At first, the speech recognition threshold (SRT) for 85% correct sentence identification using HINT sentences will be determined by adaptively varying the signal-to-noise ratio of the sentence using speech-shaped noise. Each subject-specific SNR will be used in all of their repeated testing before and after music training. Participants will wear a 64-channel EEG cap and will be seated in a circular speaker ring array with a computer screen indicating instructions. The sentences will be presented by a speaker directly in front of the listener, while the other seven speakers will play speech babble. The test procedure will comprise twenty blocks of five HINT sentences in noise (SNR for 85% correct), where each block will include five trials of a list of six sentences. The participant will repeat the final word in each sentence (identification task). After each list, the participant will be asked to verbally repeat the last six words in any order (free recall task). The approximate time for this procedure will last about 50 min, including 10 min for the free recall task.

As mentioned before in Section 1.4 the SWIR test protocol enables the assessment of cognitive recall performance (WM) as indexed by the recall of the six final words of the sentence as well as subsequent speech understanding in noise.