Articulatory Suppression - Irrelevant Speech

Irrelevant Speech

Excessive research has been done to assess the relationship between articulatory suppression and irrelevant speech. One within-groups research study in particular examined whether articulatory suppression has an effect on the ability to encode information into memory and the relationship that articulatory suppression has with the irrelevant speech effect. Irrelevant speech, in this experiment, consisted of words being played on a speaker during the study. Participants were shown seven letters in a row and then asked to repeat the order of the letter by pushing buttons on a screen. There were two phases to this study, and in Phase I, the participants were either asked to remain quiet while the letters were shown or to repeat “123” while the letters were shown. In Phase II, the irrelevant speech was either absent or played on the speakers.

Results of this study concluded that memory performance was disrupted by both articulatory suppression and irrelevant speech, although the effect of articulatory suppression was larger. This is because they inhibit or eliminate the individual’s ability to rely on the auditory cues that help encode information into memory. Another reason articulatory suppression inhibits memory performance more than irrelevant speech is because it prevents information from being represented in the mind and is unable to be rehearsed. In both phases, an overwhelming majority of participants did the best when the information was encoded in the quiet trial. This information could be helpful to everyone because it lends evidence to the statement that a quiet environment is the best environment for people to learn or commit any sort of information to memory.

An additional study sought to determine what types of articulatory suppression reduce the strength of encoding items into an individual’s memory. Researchers manipulated participants by engaging them in multiple kinds of articulatory suppression (i.e. some were rather easy, such as saying “the,” and some were more difficult, such as spelling a word out loud) and showing them lists to remember. Results showed that articulatory suppression of any kind reduced the strength in which an individual encoded visual information into their memory. However, participants who were in the more difficult articulatory suppression group remembered much less of the list of words than did those with an easier articulatory suppression task. The reason for this finding is because if an individual is using more effort in remembering how to do something (i.e. spell a word), they are obligated to pay less attention to additional visual information that is presented at the same time.

Hanley and Shah looked at the role of irrelevant sound effect under articulatory suppression. During this experiment, participants wore stereo headphones when being tested. During the testing, participants heard an experimental list of items through the right headphone spoken by a female voice. Participants were instructed to repeat the word “the” at a rate of approximately two repetitions per second. There was a retention interval of 10 seconds between the final item and the recall of target items. Irrelevant sound took place when a male voice was spoken in the left headphone throughout the retention interval, right before the recall of items. The results from this study showed that there was a significant effect of irrelevant sound under articulatory suppression when the list items were followed by an auditory tone, but the effect was abolished when followed by a spoken suffix.