Studies of cognition in listeners with hearing loss have not always clearly distinguished between errors of perception and errors of memory. In many discussions of intelligence, development, and aging, processing speed has been offered as the primary factor behind individual differences and age-related changes in cognition (see Park & Festini, 2017 Salthouse, 1996 Verhaeghen, 2014, for review).Įrrors of Perception Versus Errors of Memory How processing speed is related to “capacity” (i.e., the number of units that can be retained in short-term memory) is a fundamental issue, as is the question of whether processing speed is domain general (not specific to the modality of the original input) or sensory domain specific, for a given individual. Processing speed generally refers to how quickly and efficiently individuals can act upon postperceptual representations of information. Backward digit span, which requires participants to recall list items in reverse order, is usually argued to be a simple assessment of working memory. Digit span is a traditional measure of short-term memory function successful immediate recall of longer strings of digits corresponds to a higher “span.” Working memory, in contrast, subsumes short-term memory and incorporates additional attentional mechanisms for maintaining and manipulating information in conscious awareness. Short-term memory, a temporary storage system that operates within the timescale of several seconds to several minutes, appears markedly limited in capacity and is reset or cleared with the passage of time, unless effort (such as rehearsal) or other circumstance precipitates recoding into longer, lasting storage (see Baddeley, Eysenck, & Anderson, 2015, for review). Thus, use of relatively context-neutral test materials, such as spoken strings of digits, provides insight into the basic workings of memory that is mostly irrespective of language structure and world knowledge.Overview of Short-Term Memory, Working Memory, and Processing Speed For new information presented in an arbitrary order, however, such scaffolding is less helpful. In general, the adult listener with NH functions quite well despite degraded speech information, particularly when a scaffolding of learned “top-down” information exists to draw upon ( Miller & Licklider, 1950 Moore, 1997 Shannon, Zeng, Kamath, Wygonski, & Ekelid, 1995). Speech communication research has long studied the impact of noise and signal distortion on perception, with additional efforts made to measure their influence on retention. Even when hearing-assistive devices, such as cochlear implants (CIs) or hearing aids, are used to restore some of the auditory input, the sensory encodings are atypical because of the design of the electronic interface and the state of the compromised auditory processing system ( Abbas & Brown, 2015 Firszt, Chambers, Kraus, & Reeder, 2002). Hearing loss poses various challenges for auditory processing. Listeners might be less accurate at identifying a stimulus as the intended target, slower to assign a category to the stimulus, or less confident in their classification. This study of adult cochlear implant users and listeners with normal hearing (NH) addresses how degradations and distortions in the input stimulus affect initial identification (ID), storage, and recall of target information.Īuditory stimuli are more difficult to classify when the target signals are degraded or obscured by other signals. Entering a new phone number or repeating back a set of previously unfamiliar names, for example, are common situations relying on our ability to store and access material in the temporary workspace of short-term and working memory. The ability to temporarily store and recall novel sets of information varies across individuals, circumstance, and life span.

Average digit span by age