A man was telling his neighbor, "I just bought a new hearing aid. It cost me four thousand dollars, but it's state of the art. It's perfect." "Really," answered the neighbor. "What kind is it?" "Twelve thirty."
Hearing loss is no laughing matter. At almost six grand for a pair of hearing aids, it certainly is no joke, and the social consequences of hearing impairment strike quite a toll. People have joked about selective hearing ever since the phrase, “I do,” was borrowed from the courtroom. The thing is, selective hearing is real. When we complain that someone has selective hearing, we mean they ignore us when it’s convenient to them. Actually, it’s something more powerful that lies in the connection between the ears and the brain, where your auditory sense can decide what to hear and what to ignore. Why will you awaken at the slightest stirring of your newborn child, but sleep through the woodcutting of his parent? Why does the heater fan wake you in the middle of the night on a weekday, yet allow you to sleep through it on Saturday? Hearing occurs in the brain. The ears are only a conduit. The brain’s auditory system translates sound fragments that are arranged into meaningful precepts.
The Cocktail Party Effect
The cocktail party effect is a related phenomenon of auditory attention that describes a person’s ability to focus on a particular stimulus while filtering out a range of other stimuli. With selective hearing, the poor husband, for example, might truly not hear his wife ask if he wants to attend the opera, but will hear her ask if he’ll go to a baseball game next week. It’s a matter of how the brain is programmed. This is such a complex topic that the wife who asked about the opera may not hear an affirmative response because she expects not to get one. How’s that for the start of a battle?
The fact that you can hear a single voice in the middle of a noisy social gathering is referred to as a theory of selective attention, where you’re able to concentrate and focus on a single input. When you’re in a place where you’re expected to listen, whether in a classroom or lecture hall, or with a friend or your family, you bring to the conversation all of your past experiences, including the semantic memory that carries meanings and understandings of facts and general information, and the episodic memory that holds recollection of autobiographical occurrences that include times, places, and emotions. Not only these memory types, but also the directions from which voices come, your skills at lip reading and interpreting gestures, your perceptions of voices and their characteristic pitches and cadences, and the geographical accents of the speaker(s) will affect your attention and response to the spoken word (Cherry, 1953).
Two Ears Are Better Than One
Stimulating each ear at the same time with two different sounds, as in listening to the sportscaster and your spouse simultaneously, is an extraordinary feat. The auditory system has been found to localize and assign sound source characteristics when bombarded by more than one source. However, the brain will process that which is really needed or really wanted. This is predicated by attention to the aspects of the sounds that are relevant to the listener’s goal (Mesgarani, 2012) and by the sound frequencies, with bass sounds traveling farther than treble sounds. Such is partly the process by which baby penguins are able to find their mothers in a huge colony of raucous neighbors. As would be expected, repetition helps (Therese-Heemels, 1999).
Humans have the capacity to anticipate the next syllable or word to be pronounced by a speaker based on the preceding articulations and one’s experiences with English language components—phonemes and morphemes, diphthongs and digraphs, and syntax. Even if one ear is partially or wholly dysfunctional, it is possible to interpret a speaker’s message by virtue of paying attention (Okita, 2000) (McArdle, 2012). The pinna, the ear’s external flap of skin and cartilage, acts as a directional filter that helps us to distinguish front-back and above-below messages. Knowing this, attention can be so concentrated as to separate sounds from unwanted noise (Cherry, 1953). One of the aspects of language that makes this easier is the cliché, which is nothing more than a highly probable chain of words. If you’re part of a conversation in a loud room, you might instinctively turn one ear toward the speaker. The other ear will reject the message and probably disconnect from the sounds to which it is exposed (Bentin, 1995). Therefore, it’s not likely you’ll be able to extract a message from the radio personality while intently listening to your passenger.
For any of us who wishes to keep the peace, asking our significant other to get our attention before heralding any news is good science. Deciding to pay attention is being courteous. It’s also better social advice than almost anything your parents told you when you were a teenager. Are you listening?
Bentin S, Kutas M, Hillyard SA. Semantic processing and memory for attended and unattended words in dichotic listening: behavioral and electrophysiological evidence. J Exp Psychol Hum Percept Perform. 1995 Feb;21(1):54-67.
E. Colin Cherry Some Experiments on the Recognition of Speech, with One and with Two Ears J. Acoust. Soc. Am. Volume 25, Issue 5, pp. 975-979 (1953)
Cowan N, Wood NL. Constraints on awareness, attention, processing, and memory: some recent investigations with ignored speech. Conscious Cogn. 1997 Jun-Sep;6(2-3):182-203.
Marie Therese-Heemels Penguins and the ‘cocktail party effect’ Nature. doi:10.1038/news990701-12; Published online 1 July 1999 http://www.nature.com/news/1999/990701/full/news990701-12.html
Ching Kung A possible unifying principle for mechanosensation Nature 436, 647-654 (4 August 2005) | doi:10.1038/nature03896
McArdle RA, Killion M, Mennite MA, Chisolm TH. Are two ears not better than one? J Am Acad Audiol. 2012 Mar;23(3):171-81.
Nima Mesgarani & Edward F. Chang Selective cortical representation of attended speaker in multi-talker speech perception Nature (2012) doi:10.1038/nature11020
Okita T, Jibu T. Semantic processing of words in selective listening: an examination using recognition tests and event-related brain potentials. Shinrigaku Kenkyu. 2000 Apr;71(1):34-41.
Brian N. Pasley, Stephen V. David, Nima Mesgarani, Adeen Flinker, Shihab A. Shamma, Nathan E. Crone, Robert T. Knight, Edward F. Chang Reconstructing Speech from Human Auditory Cortex PLoS Biol 10(1): e1001251. doi:10.1371/journal.pbio.1001251
Varghese LA, Ozmeral EJ, Best V, Shinn-Cunningham BG.
How Visual Cues for when to Listen Aid Selective Auditory Attention.
J Assoc Res Otolaryngol. 2012 Feb 11.
*These statements have not been evaluated by the FDA. These products are not intended to treat, diagnose, cure, or prevent any disease.