Cognition Flashcards
Why can audibility alone not explain why older adults have difficulties hearing?
- Older adults frequency report difficulties understanding speech in background noise (Desjardins & Doherty, 2013)
- Both older adults with hearing loss and those with normal hearing experience difficulties understanding speech in noise
- Even with audibility accounted for, these older adults do not demonstrate improvements in speech understanding
- Young adults with similar audiometric thresholds do not demonstrate the same difficulties as their older counterparts (Schurman, Brungart, & Gordon-Salant, 2014)
- Current literature suggests that both peripheral hearing loss and cognitive decline contribute to older adults’ difficulties understanding speech in noise
What is communication?
Active process that requires that individuals recall a spoken message over time and respond appropriately
What cognitive functions are required for speech understanding in noise?
- Working memory
- Processing speed
- Selective attention (Desjardins & Doherty, 2013)
What is working memory?
- Plays an important role in understanding written and spoken information in high SNRs (Pichora-Fuller, Schneider, & Daneman, 1995)
- Working memory is responsible for the temporary storage of information required to carry out cognitive tasks, including comprehension, learning, and reasoning (Ronnberg et al., 2013)
- When communication breakdowns occur, working memory is evoked (Johns, Myers, & Skoe, 2018)
What happens when working memory capacity is reduced?
An individual is not able to easily fill in the gaps when parts of speech are missing or misunderstand
What is the ELU?
Ease of Language Understanding Model (Ronnberg et al., 2013)
- Framework for explaining the role of working memory and how it contributes to speech understanding
- Model theorizes that even when hearing losses are accounted for, individuals with lower working memory capacity will perform poorer on speech recognition tasks than their counterparts with higher working memory capacity
- When contextual cues are limited, individuals with lower working-memory capacity will perform poorer on speech recognition tasks
- Fluctuating background noise will place greater demands on working memory than steady-state background noises
What affects older adults’ speech perception in noise abilities?
- Age-related deficits in working memory
- When older adults listen in a variety of SNRs, more cognitive resources are required for speech processing, which limits the resources allocated to working memory for linguistic/cognitive processing
- Since more resources are required for working memory, top-down processing is used to process speech
- As a result, older adults exert more listening effort
Besides audibility and declines in working memory, what else affects speech understanding?
Different types of background maskers (Schurman, Brungart, & Gordon-Salant, 2014)
- Steady-state or modulated maskers produce energetic masking that causes speech recognition to deteriorate
- Portions of the target signal are made undetectable by the masker
- Competing speech also produces energetic masking, but more informational masking
What is informational masking?
Masking that occurs when the target signal and masker are similar.
- Speech recogniiton is mroe difficult in the presence of informational masking since the listener is unable to distinguish between the target signal and the masker
What else affects speech perception in the presence of informational masking?
The location of the target and masker.
- When the target speech and masker are spatially separated, young adults are able to make use of locational cues and recognize and comprehend the target speech
- Older adults still have poor speech understanding b/c they cannot make use of spatially separated signals (Helfer & Freyman, 2008)
How can the audiologist account for and assess cognitive status?
Case Hx Intake
- Conduct informal assessment by determining their level of alertness, ability to pay attention to the questions, and ability to appropriately respond to the questions being asked
Formal screening measure
- Digit Span subtest Weschler scale of Adult Intelligence
- Has published norms based on age/educational levels
What does the audiologist have to consider while conducting a cognitive screener?
Untreated hearing loss
- Untreated hearing loss can present with similar symptoms as an individual with cognitive decline
What is WDRC?
Wide dynamic range compression
- Nonlinear processing scheme that makes soft sounds audible and loud sounds comfortable
- Can make sounds distorted which negatively contributes to speech understanding
What do hearing aids provide?
HAs provide audibility but lack the ability to provide clarity of speech
Individuals with HL, treated with hearing aids, will perform worse than young normal-hearing individuals on speech perception tasks
Which time constants should be selected?
There is limited evidence-based research that helps audiologists determine which patients will benefit from slow or fast release times
- It is thought that there is a relationship between time constants and cognitive function, but the relationship is unclear (Cox & Xu, 2010)
- Studies in this area have not included many participants, utilized few outcome measures, and did not provide a time period of acclimatization (Gatehouse, Naylor, & Elberling, 2006)
- No standard protocol for selecting hearing aid parameters and considerations that will improve outcomes in older adults (Souza, 2004)
