Speech in Noise Discrimination Skills in Multiple Sclerosis Patients.

Hearing and speech tests of MS group and control group in the presence and absence of noise will be evaluated. Suppression test will be performed with OAE test in the presence and absence of noise.

Speech discrimination in noise (SDN) test will be performed in a quiet room in accordance with the Industrial Acoustic Company (IAC) standard using the Grason-Stadler GSI 61 Clinical Audiometer. After pure tone audiometry and speech tests, the GKAE test will be performed. The speech in noise discrimination test will be performed with a signal-to-noise (S/N) ratio of +10 dB. A word list at 50 dB SL will be presented to the tested ear using live sound, while simultaneously white noise at 40 dB SL will be presented to the test ear (Beattie et al. 1997). This will be done for both ears. The speech in noise discrimination test scores will be calculated as percentages (%) for both ears.

Translated into Turkish as the Montreal Cognitive Assessment Scale and abbreviated as MOBID, MOCA assesses attention, executive/managerial functions, memory, visual-spatial skills, language, abstract thinking and arithmetic. It is easy and practical to apply. The score that can be obtained varies between 0-30. The cut-off point for cognitive impairment is 21. Patients who perform below 21 points are considered to have cognitive impairment. Although it is not a battery used in the MS patient group, a study conducted on 39 MS patients and 20 healthy people showed that it can be used safely for screening purposes in patients with MS (Aksoy et al., 2013; Nasreddine et al., 2005; Selekler \& Cangoz, 2009).

Attention, visuospatial information processing speed and working memory are assessed. It is one of the subtests of the Short Repeatable Neuropsychological Battery developed to assess cognitive functions in MS (Smith, 1973).