Evaluation of sound perception using a wireless sensor network for individuals with normal hearing

The results of a psychophysical study of the characteristics of auditory perception of sound rhythmic sequences in a risk group for age-related hearing loss: elderly people aged 60 to 78 years (Group 1: = 39; M = 15, F = 24, normal hearing according to pure tone threshold audiometry) were presented. The comparison groups included young subjects aged 18 to 30 years with normal hearing (Group 2: = 47; 24 men and 23 women) and elderly people aged 62 to 76 years with grade 2 bilateral sensorineural hearing loss who do not use hearing aids (Group 3: = 30; 14 men and 16 women). Age and gender differences in rhythm recognition were analyzed. The experimental stimuli corresponded to sequences of 3 tone bursts (F = 1000 H2) of varying duration (300, 600 ms; 150 ms pause), forming 6 rhythmic pattern variants (long-short-long, short-short-long, etc.). Additionally, 20 elderly subjects from Group 1 and 22 young subjects from Group 2 took part in short-term auditory memory testing using the auditory digit series reproduction method (Jacobs test). The correlation between the indicators of rhythmic pattern recognition and auditory memory was assessed. The obtained data confirmed the influence of age and hearing condition on rhythm perception. The reliable decrease in its indicators (p < 0.01) observed in elderly subjects with normal hearing thresholds. In this group, gender differences in the “success” of auditory rhythm perception and their relationship with the characteristics of short-term auditory memory were also evident. The results are discussed in the context of using rhythmic sound sequences in testing programs and sensory-cognitive training for the early detection and prevention of age-related hearing problems, including central auditory analysis and auditory memory processes.

We are generally able to identify sounds and understand speech with ease, despite the large variations in the acoustics of each sound, which occur due to factors such as different talkers, background noise, and room acoustics. This form of perceptual constancy is likely to be mediated in part by the auditory system's ability to adapt to the ongoing environment or context in which sounds are presented. Auditory context effects have been studied under different names, such as spectral contrast effects in speech and auditory enhancement effects in psychoacoustics, but they share some important properties and may be mediated by similar underlying neural mechanisms. This review provides a survey of recent studies from our laboratory that investigate the mechanisms of speech spectral contrast effects and auditory enhancement in people with normal hearing, hearing loss, and cochlear implants. We argue that a better understanding of such context effects in people with normal hearing may allow us to restore some of these important effects for people with hearing loss via signal processing in hearing aids and cochlear implants, thereby potentially improving auditory and speech perception in the complex and variable everyday acoustic backgrounds that surround us.

Introduction: Hearing impairment affects all aspect of individual life, especially auditory perception, while use of cochlear implant or hearing aids has been associated with appropriate effects in auditory performance. The aim of the present research was to comparing auditory perception in children with cochlear implant, hearing aids and normal hearing in Tehran province. Materials and Methods: In this analytic and comparative research, were participated 60 male children aged 5–7 years. They were divided into three groups and each group was consisted 20 children. First and second group were selected, ordinarily, from children with cochlear implant and hearing aids by in available method; while that third group were selected from children with normal hearing by randomly method. The instruments of this research were Raven intelligence test and Categories of Auditory Performance scale (CAP). The obtained data were statistically analyzed by one-way ANOVA and Post-Hoc Scheffe in SPSS 16 software. Results: There was a significant difference between scores mean of auditory perception in three groups (F (2, 57) = 42.99, P<0.0005). The scores mean of auditory perception in normal hearing children was more than children into other groups, significantly (P<0.0005). Also, scores mean of auditory perception in children with cochlear implant was more than children with hearing aids, significantly (P<0.002). Conclusion: Auditory perception in children with normal hearing was better than children with cochlear implant or hearing aids. Since, use of cochlear implant and hearing aids led to improvement of auditory perception in deaf children. Therefore, require unique rehabilitation program in order to achieve more development auditory performance skill of children with cochlear implant or hearing aids. Keywords: auditory perception, cochlear implant, hearing aids, deaf children

Daily Sound Awareness of CI Users

The purposes of this study were to: 1) develop a scoring system to assess narrative ability in children; 2) evaluate the impact of auditory speech perception with a cochlear implant on narrative ability; and 3) evaluate the importance of narrative ability to reading comprehension in deaf children. Narrative productions prompted from an eight-picture sequence story were elicited from 8 and 9 yr olds; 87 who had at least 4 yr of cochlear implant experience and 28 who had normal hearing. The stories were transcribed and a scoring system for narrative ability was developed based on the use of complete narrative structure, conjunctions linking semantic relations, and referents that served to identify and distinguish characters in the narrative. Narrative ability scores of cochlear implant users were examined in relation to their age, IQ, speech perception, language, and reading test scores. In addition, narrative ability scores for children with normal hearing were compared with two groups of cochlear implant users, those with above average speech perception scores and those with below average speech perception scores. Within the sample of hearing-impaired children, narrative ability scores correlated significantly with speech perception, language syntax, and reading test scores. A multiple regression analysis was conducted to predict reading comprehension scores from four predictor variables (age, IQ, language syntax, and narrative ability). Results reflected the independent contribution of discourse-level language skills, as measured by the narrative ability score, as well as sentence-level language skills in predicting reading test scores. Analysis of stories obtained from 8- and 9-yr-old children with normal hearing revealed the classic pattern that included a high point, a resolution, and one or more evaluative statements. Their stories achieved cohesion from correct use of both conjunctions and referents. Deaf children who received above-average speech perception scores with a cochlear implant (i.e., scored above 48% on the Word Intelligibility by Picture Identification speech perception test) told narratives that were similar in structure and use of referents to those of age mates with normal hearing. Although their use of subordinate conjunctions was not as well developed as normal-hearing children, it was significantly above that of deaf children who received less speech perception benefit after a similar period of implant use. These below-average speech perceivers exhibited significantly poorer use of narrative structure and cohesive devices than either normal-hearing age mates or children who achieved above average speech perception with a cochlear implant. Narrative ability is an important predictor of reading comprehension ability in deaf children above and beyond IQ and syntactic competence. Children who receive a cochlear implant under 5 yr of age and obtain above average speech perception benefit from the device construct narratives that are similar in structure and cohesion to those of their hearing age mates by age 8 to 9.

Cochlear implants (CIs) are auditory prostheses that restore hearing via electrical stimulation of the auditory nerve. Compared to normal acoustic hearing, sounds transmitted through the CI are spectro-temporally degraded, causing difficulties in challenging listening tasks such as speech intelligibility in noise and perception of music. In normal hearing (NH), musicians have been shown to better perform than non-musicians in auditory processing and perception, especially for challenging listening tasks. This “musician effect” was attributed to better processing of pitch cues, as well as better overall auditory cognitive functioning in musicians. Does the musician effect persist when pitch cues are degraded, as it would be in signals transmitted through a CI? To answer this question, NH musicians and non-musicians were tested while listening to unprocessed signals or to signals processed by an acoustic CI simulation. The task increasingly depended on pitch perception: (1) speech intelligibility (words and sentences) in quiet or in noise, (2) vocal emotion identification, and (3) melodic contour identification (MCI). For speech perception, there was no musician effect with the unprocessed stimuli, and a small musician effect only for word identification in one noise condition, in the CI simulation. For emotion identification, there was a small musician effect for both. For MCI, there was a large musician effect for both. Overall, the effect was stronger as the importance of pitch in the listening task increased. This suggests that the musician effect may be more rooted in pitch perception, rather than in a global advantage in cognitive processing (in which musicians would have performed better in all tasks). The results further suggest that musical training before (and possibly after) implantation might offer some advantage in pitch processing that could partially benefit speech perception, and more strongly emotion and music perception.

We present NeuroVoc, a flexible model-agnostic vocoder framework that reconstructs acoustic waveforms from simulated neural activity patterns using an inverse Fourier transform. The system applies straightforward signal processing to neurogram representations, time-frequency binned outputs from auditory nerve fiber models. Crucially, the model architecture is modular, allowing for easy substitution or modification of the underlying auditory models. This flexibility eliminates the need for speech-coding-strategy-specific vocoder implementations when simulating auditory perception in cochlear implant (CI) users. It also allows direct comparisons between normal hearing (NH) and electrical hearing (EH) models, as demonstrated in this study. The vocoder preserves distinctive features of each model; for example, the NH model retains harmonic structure more faithfully than the EH model. We evaluated perceptual intelligibility in noise using an online Digits-in-Noise (DIN) test, where participants completed three test conditions: one with standard speech, and two with vocoded speech using the NH and EH models. Both the standard DIN test and the EH-vocoded groups were statistically equivalent to clinically reported data for NH and CI listeners. On average, the NH and EH vocoded groups increased SRT compared to the standard test by 2.4 dB and 7.1 dB, respectively. These findings show that, although some degradation occurs, the vocoder can reconstruct intelligible speech under both hearing models and accurately reflects the reduced speech-in-noise performance experienced by CI users.

Purpose Attaining speech accuracy requires that children perceive and attach meanings to vocal output on the basis of production system capacities. Because auditory perception underlies speech accuracy, profiles for children with hearing loss (HL) differ from those of children with normal hearing (NH). Method To understand the impact of auditory history on emergence of speech capacities, the authors compared consonant–vowel (CV) syllable accuracy in early words in 4 NH children and 4 children with HL who received cochlear implantation (CI) before age 2 years. Participants were video-recorded monthly for 6 months following word onset. CV vocalizations were coded perceptually with broad phonetic transcription. Observed-to-expected ratios of CV productions and accuracy were tested with chi-square analysis. An ordered multinomial model tested level of accuracy, including both accuracy and error patterns. Results Most frequently produced sequences were most accurately produced across group and time. NH children were more accurate overall than children with CI. Both groups improved accuracy over time by decreasing partially accurate productions (accurate consonant–inaccurate vowel). Both groups favored CV patterns with compatible place of articulation between consonant and vowel in absolute frequency and level of accuracy. Conclusion Differences in emergence of CV syllable accuracy arise from differences in auditory perception between the NH and CI groups.

Background and Aim: Caffeine intake enhances concentration through affecting brain functions. It also improves attention to the signal which is believed to be associated with increased noise tolerance and improved speech perception. This study aimed to evaluate the long-term effects of caffeine intake on simultaneous speech and sound perception in people with normal hearing.&#x0D; Methods: This double-blind study was conducted on 90 people aged 18-34 years (45 males and 45 females), randomly assigned to two intervention groups (receiving 3 and 5 mg/kg caffeine) and a control group (receiving placebo). The acceptable noise level (ANL) test was conducted before and five hours after intervention.&#x0D; Results: Comparison of ANL scores before and after intervention showed a significant difference in the 3 mg/kg caffeine group (p=0.002), but not in the placebo (p=0.497) and 5 mg/kg caffeine (p=0.146) groups. Between-group analysis showed a significant difference between the placebo and 3 mg/kg caffeine groups in the ANL five hours after (p=0.005), while the difference was not significant between the placebo and the 5 mg/kg caffeine groups (p=0.139). Moreover, there was no significant difference in the ANL between the 3 and 5 mg/ kg caffeine groups (p=0.148).&#x0D; Conclusion: Caffeine intake affects noise tolerance, depending on the dose of caffeine. The ANL and speech tolerance improve five hours after consuming 3 mg/kg of caffeine.&#x0D; Keywords: Caffeine; noise perception; normal hearing; acceptable noise level test

The majority of psychoacoustic research investigating sound localization has utilized stationary sources, yet most naturally occurring sounds are in motion, either because the sound source itself moves, or the listener does. In normal hearing (NH) listeners, previous research showed the extent to which sound duration and velocity impact the ability of listeners to detect sound movement. By contrast, little is known about how listeners with hearing impairments perceive moving sounds; the only study to date comparing the performance of NH and bilateral cochlear implant (BiCI) listeners has demonstrated significantly poorer performance on motion detection tasks in BiCI listeners. Cochlear implants, auditory protheses offered to profoundly deaf individuals for access to spoken language, retain the signal envelope (ENV), while discarding temporal fine structure (TFS) of the original acoustic input. As a result, BiCI users do not have access to low-frequency TFS cues, which have previously been shown to be crucial for sound localization in NH listeners. Instead, BiCI listeners seem to rely on ENV cues for sound localization, especially level cues. Given that NH and BiCI listeners differentially utilize ENV and TFS information, the present study aimed to investigate the usefulness of these cues for auditory motion perception. We created acoustic chimaera stimuli, which allowed us to test the relative contributions of ENV and TFS to auditory motion perception. Stimuli were either moving or stationary, presented to NH listeners in free field. The task was to track the perceived sound location. We found that removing low-frequency TFS reduces sensitivity to sound motion, and fluctuating speech envelopes strongly biased the judgment of sounds to be stationary. Our findings yield a possible explanation as to why BiCI users struggle to identify sound motion, and provide a first account of cues important to the functional aspect of auditory motion perception.

Selecting Speech Tests to Measure Auditory Function

Fast- and slow-acting amplitude compression parameters have complementary strengths and weaknesses that limit the full benefit of this feature to hearing aid users. Adaptive time constants have been suggested in the literature as a means of optimizing the benefits of amplitude compression. The purpose of this study was to compare the effects of three amplitude compression release times (slow, fast, and adaptive) on children's and adults' accuracy for categorizing speech and environmental sounds. Participants were asked to categorize speech or environmental sounds embedded in short trials containing low-level playground noise. Stimulus trials included either a high-level environmental sound followed by a lower-level speech stimulus (word) or a high-level speech stimulus followed by a lower-level environmental sound. The listeners responded to the second (low-level) stimulus in each trial. The two stimuli overlapped temporally in half of the trials but not in the other half. The stimulus trials were processed to simulate amplitude compression having fast (40 msec), slow (800 msec), or adaptive release times. The adaptive-compression parameters operated in a slow fashion until a sudden increase/decrease in level required a rapid change in gain. Participants were 15 children and 26 adults with hearing loss (HL) as well as 20 children and 21 adults with normal hearing (NH). DATA COLLECTION AND ANALYSES: Performance (in % correct) was arcsine transformed and subjected to repeated-measures analysis of variance with pairwise comparisons of significant main effects using Bonferroni adjustments for multiple comparisons. Overall, the performance of listeners with HL was poorer than that of the listeners with NH and performance for the environmental sounds was poorer than for the speech stimuli, particularly for the adults and children with HL. Significant effects of age group, stimulus overlap, and compression speed were observed for the listeners with NH, whereas effects of stimulus overlap and compression speed were found for the listeners with HL. Whereas listeners with NH achieved optimal performance with slow-acting compression, the listeners with HL achieved optimal performance with adaptive compression. Although slow, fast, and adaptive compression affects the acoustic signal in a subtle fashion, amplitude compression significantly affects perception of speech and environmental sounds.

In this paper, a simple analysis has been made to distinguish the normal and abnormal hearing subjects using acoustically stimulated EEG signals. Independent power spectral features of the brain rhythms (delta, theta, alpha, beta, and gamma) were extracted from the recorded EEG signals. The extracted power spectral features were then associated to the auditory perception and neural network models for the left and right ears were developed. The result indicates that the gamma-power derived from the electrodes can be deployed independently to characterize the EEG dynamics of normal hearing and abnormal hearing perception of a person. The effects of brain rhythms on perceiving two different auditory frequencies namely 500 Hz and 1000 Hz their associated auditory response have been investigated. From the network models, it has been inferred that the neural network models were able to discriminate the normal hearing and abnormal hearing persons.

Central auditory processing disorder (CAPD) is defined as “a deficit in the perceptual processing of auditory stimuli and the neurobiological activity underlying that processing.”1 (C)APD likely arises from abnormal neural representation of speech and non-speech sounds in the central auditory nervous system (CANS). This type of disorder may occur in pediatric and adult patients with normal hearing or may co-exist with, or occur secondary to, peripheral hearing loss. (C)APD may lead to difficulties in various auditory functions that are important for listening and comprehending spoken language, especially in noisy backgrounds. As such, (C)APD deficits may include difficulty with lateralization, localization, auditory discrimination, auditory pattern recognition, other temporal processing deficits, and more.1 Generally, patients with (C)APD are children presenting with listening problems in the classroom and difficulty in academic pursuits. (C)APD may be associated with learning disorders, especially in the areas of reading, spelling, articulation problems, difficulty following directions, and significant challenges regarding communicating and comprehending.2,3 (C)APD is more common in boys than girls and even more common in children with a significant history of otitis media.4 Roughly 7% of children are estimated to have (C)APD.5 (C)APD must be diagnosed using tools previously shown to have validity for identification of CANS dysfunction.1 Unfortunately, diagnostic tools currently available do not allow evaluation of (C)APD in children below 7 years of age, secondary to variability in the development of the brain and central nervous system. Other common disorders can mimic or co-exist with (C)APD. For example, attention deficit hyperactivity disorder (ADHD), autism, language processing disorder, and various cognitive disorders may lead to listening behaviors similar to those of (C)APD. However, the diagnosis of (C)APD is not appropriate when listening difficulties arise from, or are due to, higher-order, pan-sensory or global disorders, unless concomitant dysfunction in the CANS can be demonstrated.1 Therefore, with respect to pediatric applications, a multidisciplinary team-based approach involving the audiologist, parent(s), physician, speech-language pathologist, teacher, school psychologist, and possibly others is critical to ensure that all behaviors, actions, and observations have been addressed and considered, prior to arriving at a differential diagnosis.1-3

Tinnitus is the perception of a sound without an external source. It can affect auditory perception abilities in individuals with normal hearing sensitivity. The aim of the study was to determine the effect of tinnitus on psychoacoustic abilities in individuals with normal hearing sensitivity. The study was conducted on twenty subjects with tinnitus and twenty subjects without tinnitus. Tinnitus group was again divided into mild and moderate tinnitus based on the tinnitus handicap inventory. Differential limen of intensity, differential limen of frequency, gap detection test, modulation detection thresholds were done through the mlp toolbox in Matlab and speech in noise test was done with the help of Quick SIN in Kannada. RESULTS of the study showed that the clinical group performed poorly in all the tests except for differential limen of intensity. Tinnitus affects aspects of auditory perception like temporal resolution, speech perception in noise and frequency discrimination in individuals with normal hearing. This could be due to subtle changes in the central auditory system which is not reflected in the pure tone audiogram.