Informational Masking Effects of Speech Versus Nonspeech Noise on Cortical Auditory Evoked Potentials

2021 ◽  
Vol 64 (10) ◽  
pp. 4014-4029
Author(s):  
Kathy R. Vander Werff ◽  
Christopher E. Niemczak ◽  
Kenneth Morse

Purpose Background noise has been categorized as energetic masking due to spectrotemporal overlap of the target and masker on the auditory periphery or informational masking due to cognitive-level interference from relevant content such as speech. The effects of masking on cortical and sensory auditory processing can be objectively studied with the cortical auditory evoked potential (CAEP). However, whether effects on neural response morphology are due to energetic spectrotemporal differences or informational content is not fully understood. The current multi-experiment series was designed to assess the effects of speech versus nonspeech maskers on the neural encoding of speech information in the central auditory system, specifically in terms of the effects of speech babble noise maskers varying by talker number. Method CAEPs were recorded from normal-hearing young adults in response to speech syllables in the presence of energetic maskers (white or speech-shaped noise) and varying amounts of informational maskers (speech babble maskers). The primary manipulation of informational masking was the number of talkers in speech babble, and results on CAEPs were compared to those of nonspeech maskers with different temporal and spectral characteristics. Results Even when nonspeech noise maskers were spectrally shaped and temporally modulated to speech babble maskers, notable changes in the typical morphology of the CAEP in response to speech stimuli were identified in the presence of primarily energetic maskers and speech babble maskers with varying numbers of talkers. Conclusions While differences in CAEP outcomes did not reach significance by number of talkers, neural components were significantly affected by speech babble maskers compared to nonspeech maskers. These results suggest an informational masking influence on neural encoding of speech information at the sensory cortical level of auditory processing, even without active participation on the part of the listener.

2006 ◽  
Vol 17 (08) ◽  
pp. 559-572 ◽  
Author(s):  
Katrina Agung ◽  
Suzanne C. Purdy ◽  
Catherine M. McMahon ◽  
Philip Newall

There has been considerable recent interest in the use of cortical auditory evoked potentials (CAEPs) as an electrophysiological measure of human speech encoding in individuals with normal as well as impaired auditory systems. The development of such electrophysiological measures such as CAEPs is important because they can be used to evaluate the benefits of hearing aids and cochlear implants in infants, young children, and adults that cannot cooperate for behavioral speech discrimination testing. The current study determined whether CAEPs produced by seven different speech sounds, which together cover a broad range of frequencies across the speech spectrum, could be differentiated from each other based on response latency and amplitude measures. CAEPs were recorded from ten adults with normal hearing in response to speech stimuli presented at a conversational level (65 dB SPL) via a loudspeaker. Cortical responses were reliably elicited by each of the speech sounds in all participants. CAEPs produced by speech sounds dominated by high-frequency energy were significantly different in amplitude from CAEPs produced by sounds dominated by lower-frequency energy. Significant effects of stimulus duration were also observed, with shorter duration stimuli producing larger amplitudes and earlier latencies than longer duration stimuli. This research demonstrates that CAEPs can be reliably evoked by sounds that encompass the entire speech frequency range. Further, CAEP latencies and amplitudes may provide an objective indication that spectrally different speech sounds are encoded differently at the cortical level.


2016 ◽  
Vol 21 (02) ◽  
pp. 134-139 ◽  
Author(s):  
Ana Perez ◽  
Karin Ziliotto ◽  
Liliane Pereira

Introduction Long latency auditory evoked potentials, especially P300, have been used for clinical evaluation of mental processing. Many factors can interfere with Auditory Evoked Potential - P300 results, suggesting large intra and inter-subject variations. Objective The objective of the study was to identify the reliability of P3 components (latency and amplitude) over 4–6 weeks and the most stable auditory stimulus with the best test-retest agreement. Methods Ten normal-hearing women participated in the study. Only subjects without auditory processing problems were included. To determine the P3 components, we elicited long latency auditory evoked potential (P300) by pure tone and speech stimuli, and retested after 4–6 weeks using the same parameters. We identified P300 latency and amplitude by waveform subtraction. Results We found lower coefficient of variation values in latency than in amplitude, with less variability analysis when speech stimulus was used. There was no significant correlation in latency measures between pure tone and speech stimuli, and sessions. There was a significant intrasubject correlation between measures of latency and amplitude. Conclusion These findings show that amplitude responses are more robust for the speech stimulus when compared with its pure tone counterpart. The P300 indicated stability for latency and amplitude measures when the test-retest was applied. Reliability was higher for amplitude than for latency, with better agreement when the pure tone stimulus was used. However, further research with speech stimulus is needed to clarify how these stimuli are processed by the nervous system.


2014 ◽  
Vol 155 (38) ◽  
pp. 1524-1529
Author(s):  
Ádám Bach ◽  
Ferenc Tóth ◽  
Vera Matievics ◽  
József Géza Kiss ◽  
József Jóri ◽  
...  

Introduction: Cortical auditory evoked potentials can provide objective information about the highest level of the auditory system. Aim: The purpose of the authors was to introduce a new tool, the “HEARLab” which can be routinely used in clinical practice for the measurement of the cortical auditory evoked potentials. In addition, they wanted to establish standards of the analyzed parameters in subjects with normal hearing. Method: 25 adults with normal hearing were tested with speech stimuli, and frequency specific examinations were performed utilizing pure tone stimuli. Results: The findings regarding the latency and amplitude analyses of the evoked potentials confirm previously published results of this novel method. Conclusions: The HEARLAb can be a great help when performance of the conventional audiological examinations is complicated. The examination can be performed in uncooperative subjects even in the presence of hearing aids. The test is frequency specific and does not require anesthesia. Orv. Hetil., 2014, 155(38), 1524–1529.


2021 ◽  
Author(s):  
Shannon L.M. Heald ◽  
Stephen C. Van Hedger ◽  
John Veillette ◽  
Katherine Reis ◽  
Joel S. Snyder ◽  
...  

AbstractThe ability to generalize rapidly across specific experiences is vital for robust recognition of new patterns, especially in speech perception considering acoustic-phonetic pattern variability. Behavioral research has demonstrated that listeners are rapidly able to generalize their experience with a talker’s speech and quickly improve understanding of a difficult-to-understand talker without prolonged practice, e.g., even after a single training session. Here, we examine the differences in neural responses to generalized versus rote learning in auditory cortical processing by training listeners to understand a novel synthetic talker using a Pretest-Posttest design with electroencephalography (EEG). Participants were trained using either (1) a large inventory of words where no words repeated across the experiment (generalized learning) or (2) a small inventory of words where words repeated (rote learning). Analysis of long-latency auditory evoked potentials at Pretest and Posttest revealed that while rote and generalized learning both produce rapid changes in auditory processing, the nature of these changes differed. In the context of adapting to a talker, generalized learning is marked by an amplitude reduction in the N1-P2 complex and by the presence of a late-negative (LN) wave in the auditory evoked potential following training. Rote learning, however, is marked only by temporally later source configuration changes. The early N1-P2 change, found only for generalized learning, suggests that generalized learning relies on the attentional system to reorganize the way acoustic features are selectively processed. This change in relatively early sensory processing (i.e. during the first 250ms) is consistent with an active processing account of speech perception, which proposes that the ability to rapidly adjust to the specific vocal characteristics of a new talker (for which rote learning is rare) relies on attentional mechanisms to adaptively tune early auditory processing sensitivity.Statement of SignificancePrevious research on perceptual learning has typically examined neural responses during rote learning: training and testing is carried out with the same stimuli. As a result, it is not clear that findings from these studies can explain learning that generalizes to novel patterns, which is critical in speech perception. Are neural responses to generalized learning in auditory processing different from neural responses to rote learning? Results indicate rote learning of a particular talker’s speech involves brain regions focused on the memory encoding and retrieving of specific learned patterns, whereas generalized learning involves brain regions involved in reorganizing attention during early sensory processing. In learning speech from a novel talker, only generalized learning is marked by changes in the N1-P2 complex (reflective of secondary auditory cortical processing). The results are consistent with the view that robust speech perception relies on the fast adjustment of attention mechanisms to adaptively tune auditory sensitivity to cope with acoustic variability.


Author(s):  
Pamela Papile Lunardelo ◽  
Marisa Tomoe Hebihara Fukuda ◽  
Patricia Aparecida Zuanetti ◽  
Ângela Cristina Pontes-Fernandes ◽  
Marita Iannazzo Ferretti ◽  
...  

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
W A Elkholy ◽  
D M Hassan ◽  
N A Shafik ◽  
Y E K Eltoukhy

Abstract Background Cortical auditory evoked potentials (CAEPs) are brain responses evoked by sound and are processed in or near the auditory cortex. ACC is a cortical auditory evoked potential (P1-N1-P2) elicited by a change within an ongoing sound stimulus. Objective To reach the best stimuli that can elicit ACC and act as an objective tool for assessment of cortical auditory discrimination in normal hearing children. Patients and Methods The present study was originally designed to standardize ACC evoked response in 41 children aged from 2 to 10 years. The mean age in our study group was 6.2 years with no significant difference between males and females. Stimuli used in this study were specifically designed to be used by AEP equipment that is capable of uploading short duration stimuli (500 msec.), thus can be used in a regular AEP lab. ACC was elicited by three groups of stimuli. Gap-in-tones stimuli represent temporal change (6, 10, 30 and 50 msec. gap introduced to 1000 Hz tone separately), frequency pairs stimuli represent frequency change (2%, 4%, 10% and 25% change from base freq. 1000 Hz) and vowel pairs stimuli represent spectral change (/i-u/, /u-i/, /i-a/. /a-i/, /u-a/, /a-u/). ACC response parameters were compared when using the different stimuli as regards percent detectability, morphology, latency and amplitude. Results Gap-in-tones at 6 msec. and 4% frequency change could elicit ACC response in 100% of subjects. For spectral change, /u-i/ was the highest in eliciting ACC (78%) followed by /i-u/ (68.2%) then /a-i/ (58.5%). ACC had the same morphology of the onset response in the majority of subjects, with longer latency and smaller amplitude. ACC amplitude is a better indicator of cortical discrimination compared to latency because it is consistently affected by magnitude of change. Conclusion ACC is a good electrophysiological tool for cortical auditory discrimination for temporal, frequency and spectral change.


2018 ◽  
Vol 29 (07) ◽  
pp. 568-586 ◽  
Author(s):  
Jennifer L. Smart ◽  
Suzanne C. Purdy ◽  
Andrea S. Kelly

AbstractPersonal frequency modulation (FM) systems are often recommended for children diagnosed with auditory processing disorder (APD) to improve their listening environment in the classroom. Further evidence is required to support the continuation of this recommendation.To determine whether personal FM systems enhance auditory processing abilities and classroom listening in school-aged children with APD.Two baseline assessments separated by eight weeks were undertaken before a 20-week trial of bilateral personal FM in the classroom. The third assessment was completed immediately after the FM trial. A range of behavioral measures and speech-evoked cortical auditory evoked potentials (CAEPs) in quiet and in noise were used to assess auditory processing and FM outcomes. Perceived listening ability was assessed using the Listening Inventory for Education–United Kingdom version (LIFE-UK) questionnaire student and teacher versions, and a modified version of the LIFE-UK questionnaire for parents.Twenty-eight children aged 7–12 years were included in this intervention study. Of the 28 children, there were 22 males and six females.APD Tests scores and CAEP peak latencies and amplitudes were analyzed using repeated measures analysis of variance to determine whether results changed over the two baseline assessments and after the FM trial. The LIFE-UK was administered immediately before and after the FM trial. Student responses were analyzed using paired t-tests. Results are described for the (different) pre- and post-trial teacher versions of the LIFE-UK.Speech in spatial noise (SSN) scores improved by 13% on average when participants wore the FM system in the laboratory. Noise resulted in increased P1 and N2 latencies and reduced N2 amplitudes. The impact of noise on CAEP latencies and amplitudes was significantly reduced when participants wore the FM. Participants’ LIFE-UK responses indicated significant improvements in their perceived listening after the FM trial. Most teachers (74%) reported the trial as successful, based on LIFE-UK ratings. Teachers’ and parents’ questionnaire ratings indicated good agreement regarding the outcomes of the FM trial. There was no change in compressed and reverberated words, masking level difference, and sustained attention scores across visits. Gaps in noise, dichotic digits test, and SSN (hard words) showed practice effects. Frequency pattern test and SSN easy word scores did not change between baseline visits, and improved significantly after the FM trial. CAEP N2 latencies and amplitudes changed significantly across visits; changes occurred across the baseline and the FM trial period.Personal FM systems produce immediate speech perception benefits and enhancement of speech-evoked cortical responses in noise in the laboratory. The 20-week FM trial produced significant improvements in behavioral measures of auditory processing and participants’ perceptions of their listening skills. Teacher and parent questionnaires also indicated positive outcomes.


2021 ◽  
Vol 15 ◽  
Author(s):  
Hanne Gommeren ◽  
Joyce Bosmans ◽  
Emilie Cardon ◽  
Griet Mertens ◽  
Patrick Cras ◽  
...  

Background: Alzheimer’s disease (AD) is the most prevalent cause of dementia which affects a growing number of people worldwide. Early identification of people at risk to develop AD should be prioritized. Hearing loss is considered an independent potentially modifiable risk factor for accelerated cognitive decline and dementia in older adults. The main outcome of interest of this review is the alteration of Cortical Auditory Evoked Potential (CAEP) morphology in an AD or mild cognitive impairment (MCI) population with and without hearing loss.Methods: Two investigators independently and systematically searched publications regarding auditory processing on a cortical level in people with cognitive impairment (MCI or AD) with and without hearing loss. Only articles which mentioned at least one auditory elicited event-related potential (ERP) component and that were written in English or Dutch were included. Animal studies were excluded. No restrictions were imposed regarding publication date. The reference list of potential sources were screened for additional articles.Results: This systematic review found no eligible articles that met all inclusion criteria. Therefore, no results were included, resulting in an empty systematic review.Conclusion: In general, dysfunction – being either from cognitive or auditory origin – reduces CAEP amplitudes and prolongs latencies. Therefore, CAEPs may be a prognostic indicator in the early stages of cognitive decline. However, it remains unclear which CAEP component alteration is due to cognitive impairment, and which is due to hearing loss (or even both). In addition, vestibular dysfunction – associated with hearing loss, cognitive impairment and AD – may also alter CAEP responses. Further CAEP studies are warranted, integrating cognitive, hearing, and vestibular evaluations.


Sign in / Sign up

Export Citation Format

Share Document