The auditory-working memory training (AT-WMT) program is home-delivered, non-clinician-administered, and computer-based. That is, training will be self-paced and administered by the participants themselves at home using a computer. A software program has been created to facilitate the administration. Participants will spend one hour per day and five days per week for 4 weeks on training.

During the training, the following two adaptive tasks will be administered simultaneously: repeating the sentences masked by noise (i.e., AT component) and recalling the first or the final two words of all sentences in a given sentence set (i.e., WMT component).

The sentences used in the AT program are the same as those in the AT-WMT program. However, only the AT component (i.e., adaptive sentence perception in noise) of the AT-WMT program is required in the AT program. Participants do not need to recall the first or the final two words of the sentences. The same software in the experimental group will be used. Participants will spend one hour per day and five days per week for 4 weeks on training.

Participants in this group will participate in a mindfulness training program using newlife.330 (Psychiatric Rehabilitation Association, 2018) which is a Cantonese online platform for self-guided mindfulness training. The time and computer use of the active-control group will match to those of the above two groups.

The AT-WMT program is comprised of 1,200 daily used sentences either created or selected from newspapers, books, TV programs and magazines by the research assistants. The sentences are political-, cultural-, and religious-neutral sentences. Each of them contains 10 words. Noise was recorded from the upper and lower decks of a bus, in a café, a Chinese restaurant, an MTR (the Mass Transit Railway) carriage, and from a street.

During the training, the following two adaptive tasks will be administered simultaneously: repeating the sentences masked by noise (i.e., AT component) and recalling the first or the final two words of all sentences in a given sentence set (i.e., WMT component).

The Cantonese version of the Hearing in Noise Test (CHINT) (Wong & Soli, 2005) will be used to measure sentence perception in noise. The tool contains 12 lists of 20 sentences, and each sentence comprises 10 words. A high inter-list reliability has been previously demonstrated, which suggests that the lists are equivalent and, therefore, consistent results can be obtained using any of the lists (Wong et al., 2005).

The Cantonese version of the reading span test (CRST) with dual task design will be used to measure WM. It was developed based on the German reading span test (Carroll et al., 2015). The reliability and validity of the CRST have been examined to confirm that the CRST is a suitable test for investigating verbal WM (Cheung, 2021).

The CRST comprises 54 six-word sentences. The sentences are presented in different set sizes (i.e., 3, 4, 5, and 6 sentences) in random order. The participants are expected to read aloud the sentences presented on a computer screen and judge whether the sentence is semantically correct. After reading aloud all sentences in a given sentence set, the participants will be asked to recall the first or last two words of each sentence in the set. The reading span score is based on the second task: the total number of words recalled. Approximately 20 minutes is needed to complete the test.

Other cognitive functions (executive function, response inhibition, processing speed, and attention) will be examined using the CogState Battery, which is a sensitive computer-based assessment instrument. The test battery has been adapted for Chinese and its reliability and validity have been previously reported (Zhong et al., 2013). The test battery includes the following subtests and uses playing cards, digits, and pictures as stimuli: 1) One Back Test (short-term memory), 2) Groton Maze Learning Test (executive function), 3) Identification Test (Attention), 4) Go/No-Go Test (response inhibition), 5) International Digit Symbol Substitution Test-Symbols (processing speed). Each CogState subtask takes approximately 3-8 minutes. The entire CogState test battery is expected to be completed in 30-45 minutes.