AuditoryProcessing

Auditory hallucination as a result of “processing” Garrett Sneen

Auditory hallucination generally refers to the psychological disorder phenomenon by which one hears distinct voices that don’t exist. There are other phenomenons that occur in the perfectly sane that have to do with the way in which we perceive sound. Often times there are ways our mind will interpret sound by hearing something that “isn’t there.” This can happen because of “suggestions” by competing stimuli, or an attempt to familiarize and make sense of arbitrary sounds. The fact is that there is a difference between sound as an “event,” and sound perception as a mental process based on imagination and memory. The sound processing that takes place (and manufactures sound phantoms) is undoubtedly influenced by one’s culture and the concepts and labels it conjures up. In everyday listening, we don’t pay attention to the individual sounds— instead, we tend to think of the sound in terms of events, the context of the sound, and its source. Music on the other hand, is something that is listened to for its sound quality. This is most likely a result of evolution. For the sake of survival, one must be able to identify the meaning of a sound before appreciating its quality. This “mapping” or labeling is what takes place in the mind after the sound is heard, and this is what allows one to immediately think “loud sirens = danger,” instead of curiously dwelling on the type of siren it is and the quality of its tone. However, when there is no context or meaning to be found, we can map our own fabricated “sound.” These are some examples. [] Diana Deutsch has one track in particular that simply repeats two noises that are heard as distinct words (that even change the longer you listen to it) despite the language you speak. [] click the link to listen to the sample. You should hear what’s essentially a chaotic sound, but then map your own words to that sound. As you try to make out what is being “said,” you may try to force yourself to hear words, and suddenly they emerge. There are two phenomena here: one is simply mapping meaning onto chaos. The other is suggestive hearing.

In class (week 6), we tried to identify several altered melodies. What was interesting to me was that even if we had failed to recognize the melody, after knowing what to listen for it became obvious. For example, the “deck the halls” sample was devoid of a melody (the notes kept the same timing), but we were able to “hear” it because we know the melody so well that we could picture it in our heads from a simple suggestion of it. Similar to the Yankee Doodle tune we heard in class, FORCE yourself to hear the Yankee doodle tune while listening to this version with arbitrarily altered notes. (this is another Dianna Deutsch track) []

Similarly, suggestions can come from visuals. The McGurk effect is a phenomenon that shows how visual information can change auditory perception. []

Watch this clip and try to focus on what the man is saying. While the audio is “ba” the man says “ga,” but the resulting perception becomes “da.” []

more about the perception of sound as an event or idea rather than the sound itself []

more auditory misperception samples (a lot of these crashed my browser and most are pretty complicated and I don’t really understand much about them—but check them out). [|http://www.kyushu-id.ac.jp/~ynhome/ENG/Demo/illusions.html]