E-mail addresses: 01JMMAYE@alma.edu; 01BLEMER@alma.edu
Department of Psychology, Alma College, Alma, MI, 48801
In an experiment performed at Alma College, it was determined that an unattended message affects the ability to shadow. The unattended message (sound effects) occurred simultaneously as a story was shadowed in the attended ear. The sound effects either directly matched the events of the story by occuring at the same time, or the same sound effects occurred at different points in the story. The subject's recollection of the story was not affected by the matching or non-matching sound effects. However, if the events and sound effects matched, subjects recalled more of the sounds than if they did not match.
The dichotic listening task involves shadowing, which is simply repeating back words as soon as they are heard (e.g., Cherry, 1953; Moray, 1959). Using headphones, subjects hear two messages; one enters the left ear and the other enters the right. Subjects are asked to shadow one of the two messages; the message being shadowed is called the attended message. Based on early studies of dichotic listening, the question then arises as to how specific messages in the unattended ear, such as sound effects, affect shadowing. Besides affecting shadowing, sound effects in the unattended ear should affect the subject's recollection of the events heard in the left (attended) ear. To determine the effects of unattended sound effects, trials where sound effects directly correlated with events in the attended message and ones where the sound effects did not correlate could be observed. By noting areas where the subjects had difficulty shadowing and by questioning their memory of the story, the effects of sounds in the unattended ear can be determined.
Methods
The subjects were 13 students at Alma College, ranging in age from 18 to 22; eight were female and five were male. The apparatus consisted of a Macintosh computer, a compact disc player, SoundEditTM 16 version 2 Software, various compact discs, And To Think I Saw It on Mulberry Street by Dr. Seuss (1937), and It Could Always Be Worse by Margot Zemach (1976). It Could Always Be Worse was recorded and played into the left ear only. As practice, subjects were asked to shadow what they heard. The actual experiment began when subjects were asked to shadow the message in the left ear while the stimuli were presented in the right ear. In the left ear was a recording of And To Think That I Saw I t On Mulberry Street While the story played, 13 sound effects were sounded in the right ear either matching or not matching the events of the story. Subjects were asked to focus on the story, shadow it, and recall details from it once the complete story was finished. All 13 subjects heard the same story, but 6 of them heard the matching sound effects and 7 heard the same sound effects occuring during different parts of the story (non-matching). As the subjects shadowed the attended message, experimenters kept track of the words that were omitted to later observe how sound effects during the story affected shadowing. Once the entire story was heard, the experimenters asked the subjects to relay any information about the story that they recalled. They then asked the subjects to describe any sound effects heard in the right ear while shadowing the attended message.
Results
Having sound effects directly correlate with events in the story does not cause the subject to recall more events. See Figure 1 The six subjects who had matching sound effects recalled a mean of 6 events from the story out of the 13. The seven subjects who listened to the story with unmatching sound effects, however, recalled 6.71 events. See Figure 3 This does not support the initial hypothesis that matching sound effects with events would result in a better recollection of the story. However, it was found that the matching sound effects did cause the subjects to remember more sounds. See Figure 2 The mean number of sound effects recalled for the story with matching sound effects was 5, and for the non-matching story only 3.43 were recalled. See Figure 4
Sound effects in the story did affect shadowing regardless of placement. Subjects failed to shadow words at a much higher rate when sound effects were heard. The effect was stronger for sound effects that matched events than for those that did not. See Table1
Discussion
Subjects do not recall more events from the story if the events are paired with matching sound effects. This experiment did show that by having the sound effects match, subjects were more likely to recall the sound effects. The subjects listening to the matching story recalled several more sounds than those listening to the non-matching story. Subjects are more likely to make mistakes shadowing when there is a sound effect occurring in the unattended ear. There was a much greater chance of a word being missed if it had a sound effect behind it, and matching sound effects hindered shadowing slightly more than non-matching sound effects. This shows that the unattended message (the sound effects) were being processed and therefore affected the subject's ability to shadow and recall the events with a sound behind them. This supports Ambler's (1976) conclusion that processing the unattended message influenced the difficulty of shadowing the attended ear.
References
Ambler, Bruce A. (1976). Sebastiano A. Fisicaro, and Robert W. Proctor. Temporal characteristics of primary-secondary message interference in a dichotic listening task. Memory & Cognition 4, 706.
Anderson, John R., Cognitive Psychology and Its Implications, W.H. Freeman & Company, New York, 1947, 76.
Cherry, E.C. (1953). Some Experiments on the recognition of speech with one and with two ear.Journal of the Acoustical Society of America, 25, 975-979 as in Anderson, John R., Cognitive Psychology and Its Implications, W.H. Freeman & Company, New York, nbsp; 1947,76.
Menken, Alan. "Prince Ali" Aladdin Soundtrack, Walt Disney Pictures, Track 8.
Moray, N. (1959). Attention in dichotic listening: Affective cues and the influence of instruction. & Quarterly Journal of Experimental Psychology. 11, 56-60 as in Anderson, John R.,Cognitive Psychology and Its Implications, W.H. Freeman & Company, New York, 1947, 76.
"Overture" Muppet Christmas Carol SoundTrack, Jim Henson Productions, Track 1.
Prima, Louis. "Sing, Sing, Sing [With A Swing}" Swing Kids SoundTrack, EMI Robbins & Catolog, Inc., Track 1.
Seuss, Dr. (T.S. Geisel), And To Think I Saw It On Mulberry Street, Vanguard, New York, &1937.
SoundEditTM16 version 2.
Sound Effects Library, BBC Enterprise, New Jersey, 1991. CD 2,7,18,24,25,30, 37
Tangerine Dream, The Legend SoundTrack
Zemach, Margot, It Could Always Be Worse , Sunburst, Canada, 1976.