BACKGROUND AND OBJECTIVES: Mild cognitive impairment (MCI) is a disorder that usually occurs in the elderly, leading to dementia in some progressive cases. The purpose of this study is to examine the utility of central auditory processing tests as early diagnostic tools for identifying the elderly with MCI. SUBJECTS AND METHODS: This study was conducted on 20 elderly patients with MCI and 20 healthy matched peers. The speech perception ability in a quiet environment and in the presence of background noise and also temporal resolution were assessed by using Speech Perception in Noise (SPIN) and Gap in Noise (GIN) tests, respectively. RESULTS: The results indicated that the ability to understand speech in a quiet environment did not differ significantly between the two groups. However, SPIN at the three signal-tonoise ratios and the temporal resolution scores were significantly different between the two groups (p<0.001). CONCLUSIONS: Individuals with MCI appear to have poorer speech comprehension in noise and a lower temporal resolution than those of the same age, but without cognitive defects. Considering the utility of these tests in identifying cognitive problems, we propose that since the GIN test seems to be less influenced by intervening factors, this test can therefore, be a useful tool for the early screening of elderly people with cognitive problems.
Aged ; Auditory Perceptual Disorders ; Cognition ; Cognition Disorders ; Comprehension ; Dementia ; Humans ; Mass Screening ; Mild Cognitive Impairment ; Noise ; Speech Perception

Cross-modal stochastic resonance is a ubiquitous phenomenon, that is, a weak signal from one sensory pathway can be enhanced by the noise from a different sensory pathway. It is a special multisensory integration (MI) that can not be explained by the inverse-effectiveness rule. According to cross-modal stochastic resonance, the detection of signal is an inverted U-like function of the intensity of noise at different levels. In this paper, we reviewed the research of cross-modal stochastic resonance and put forward some possible explanations for it. These efforts raise a new idea for neural encoding and information processing of the brain.
Acoustic Stimulation ; Auditory Perception ; physiology ; Brain ; physiology ; Humans ; Mental Processes ; physiology ; Sensory Thresholds ; physiology ; Stochastic Processes ; Visual Perception ; physiology

In order to explore the possible mechanisms by which ethologically relevant sounds can be extracted from complex auditory environments, this study examined the effects of weak noise on the rate-intensity functions (RIFs) of neurons responding to tone burst in the inferior colliculus (IC) of nine mice (Mus musculus Km). Under free field stimuli conditions, a total of 112 IC neurons were recorded. RIFs with and without simultaneous presentation of weak noise, of which the intensity was relative to 5 dB below minimum threshold of tone burst, were measured in 44 IC neurons. By means of evaluating the changes of dynamic range (DR), slope of RIFs, and percent inhibition at different tone burst intensities evoked by the weak noise, three types of variations in RIFs were observed, i. e., inhibition (39/44, 88.6%), facilitation (2/44, 4.6%), and no effectiveness (3/44, 6.8%). Statistical analysis indicated that only inhibitory effect of weak noise was significant (P< 0.001, n = 39). The inhibitory effect of weak noise was greater at lower stimulus intensity of tone burst but decreased significantly with increased stimulus intensity (P< 0.0001, n = 39). In addition, the DR and slope of RIFs became narrower and steeper with weak noise presentation, respectively (P< 0.01, n = 31). The results from the present study suggest that weak noise exerts a dynamic modulatory action on acoustical intensity sensitivity of IC neurons, which possibly leads to a better understanding of neural mechanisms underlying the extraction of sound signals from natural auditory scenes.
Acoustic Stimulation ; Animals ; Auditory Perception ; physiology ; Auditory Threshold ; physiology ; Inferior Colliculi ; physiology ; Mice ; Neurons ; physiology ; Noise

BACKGROUND AND OBJECTIVES: Numerous studies have indicated deterioration of speech perception in noisy conditions among the elderly even those with normal hearing capabilities. The aim of this study was to investigate the effects of age on the speech-in-noise identification by speech-in-noise (SIN) test, subjective ratings of hearing difficulties by speech, spatial, and qualities of hearing scale (SSQ) questionnaire and encoding of fundamental frequency (F0) by Speech auditory brainstem response (ABR) in the elderly and comparing the results with young people. SUBJECTS AND METHODS: The present study was conducted on 32 elderly people aged over 60 years old (17 male and 15 female) with the mean age of 68.9 (standard deviation=6.33) possessing normal peripheral hearing and 32 young subjects (16 male and 16 female) aged 18-25 years old. RESULTS: Findings showed that the score of SIN test is lower among the elderly people as compared with young people in signal-to-noise ratios of 0 and -10 based on Iranian version of SSQ questionnaire (p < 0.001). The range of F0 amplitude in the elderly people is also lower than young people (p < 0.001) in Speech ABR. CONCLUSIONS: It seems that speech processing in older people is deteriorated comparing with young people regardless of their normal peripheral auditory thresholds. This decrease will result in weaker perception and improper segregation of speech from other competing sources.
Adult ; Aged ; Aging ; Auditory Threshold ; Evoked Potentials, Auditory, Brain Stem ; Hearing ; Humans ; Male ; Signal-To-Noise Ratio ; Speech Perception

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate the usefulness of speech mapping based on real ear measurement for routine hearing aid fitting and to compare functional gains for evaluating subjective satisfaction of hearing aid users. SUBJECTS AND METHOD: Twenty two participants with bilateral symmetric (< 10 dB HL difference) sensorineural hearing loss were enrolled in this study. All participants were fitted unilateral hearing aids with speech mapping using the National Acoustic Laboratories-Nonlinear 2 formula. After the initial fitting, patients were followed with the 2nd and 3rd fitting at two weeks and six weeks, respectively, and measured for aided pure tone average (PTA), aided speech discrimination score (SDS), the difference between target gain and real ear insertion gain (REIG) using speech mapping and subjective satisfaction via Korean Adaptation of the International Outcome Inventory for Hearing Aids (K-IOI-HA) questionnaire before further fitting was performed. We analyzed correlation of each parameter at 2nd and 3rd fitting with the K-IOI-HA score. RESULTS: Every sequential aided PTA and SDS at 2nd fitting and 3rd fitting were significantly improved after repeated hearing aid fitting (all p < 0.01). In the correlation analysis between K-IOI-HA and each parameter, the aided PTA and aided SDS did not show significant correlations with subjective satisfaction from the 2nd and 3rd fittings. But the difference between the target gain and R EIG in speech mapping showed significant negative correlations with the satisfaction scores at various speech level (r=–0.609 to –0.709, all p < 0.01). CONCLUSION: Speech mapping using real ear measurement was useful to expect subjective satisfaction of hearing aid users and it would be a valuable tool for fine tuning to achieve individual preferences.
Acoustics ; Auditory Threshold ; Ear ; Hearing Aids* ; Hearing Loss ; Hearing Loss, Sensorineural ; Hearing* ; Humans ; Methods ; Speech Perception

BACKGROUNDMany factors interfering with a listener attempting to grasp speech in noisy environments. The spatial hearing by which speech and noise can be spatially separated may play a crucial role in speech recognition in the presence of competing noise. This study aimed to assess whether, and to what degree, spatial hearing benefit speech recognition in young normal-hearing participants in both quiet and noisy environments.

METHODSTwenty-eight young participants were tested by Mandarin Hearing In Noise Test (MHINT) in quiet and noisy environments. The assessment method used was characterized by modifications of speech and noise configurations, as well as by changes of speech presentation mode. The benefit of spatial hearing was measured by speech recognition threshold (SRT) variation between speech condition 1 (SC1) and speech condition 2 (SC2).

RESULTSThere was no significant difference found in the SRT between SC1 and SC2 in quiet. SRT in SC1 was about 4.2 dB lower than that in SC2, both in speech-shaped and four-babble noise conditions. SRTs measured in both SC1 and SC2 were lower in the speech-shaped noise condition than in the four-babble noise condition.

CONCLUSIONSpatial hearing in young normal-hearing participants contribute to speech recognition in noisy environments, but provide no benefit to speech recognition in quiet environments, which may be due to the offset of auditory extrinsic redundancy against the lack of spatial hearing.

Adolescent ; Adult ; Auditory Threshold ; physiology ; Female ; Hearing ; physiology ; Humans ; Male ; Noise ; Speech Perception ; physiology ; Speech Reception Threshold Test ; Young Adult

INTRODUCTION: Medical school fees are rising globally. Student debt and financial background may affect residency choices, but few studies have been conducted in Asia. This study aimed to explore the relationship between financial background, student debt and postgraduate residency choices among medical students in Singapore. METHODS: An anonymised survey of all medical students in Singapore was conducted and had a response rate of 67.9%. RESULTS: 40.5% of our study population would graduate with debt. Medical students with monthly per capita household income < SGD 1,000 were more likely to graduate with debt (unadjusted odds ratio [OR] 2.0, 95% confidence interval [CI] 1.6-2.7; p < 0.001) and feel burdened by the cost of medical education (unadjusted OR 2.8, 95% CI 2.0-3.9; p < 0.001). Students with monthly per capita household income < SGD 1,000 (unadjusted OR 1.818, 95% CI 1.338-2.470, p < 0.001; adjusted OR 1.692, 95% CI 1.202-2.381, p = 0.003) and those with debt (unadjusted OR 1.623, 95% CI 1.261-2.090, p < 0.001; adjusted OR 1.393, 95% CI 1.048-1.851, p = 0.022) were more likely to rank at least one economic factor as 'very significant' in influencing their postgraduate training choices. CONCLUSION It is concerning that despite financial aid schemes, the cost of medical education remains a burden to students from lower-income households in Singapore. Student debt and financial background may distort postgraduate career choices, creating an undue push towards high-paying specialties.
Career Choice ; Choice Behavior ; Education, Medical ; economics ; Humans ; Internship and Residency ; economics ; Odds Ratio ; Schools, Medical ; economics ; Singapore ; Social Class ; Students, Medical ; statistics & numerical data ; Surveys and Questionnaires ; Training Support

PURPOSE: The purpose of this study was to describe the experience of Korean university students who participated in a therapeutic community. METHODS: Qualitative descriptive research was used. A focus group, in-depth interviews, participant-observation, and self-reports were used to collect data from 9 Korean university students. Participants lived with drug addicts for 6 weeks at DAYTOP in New York, USA. Thematic analysis was used for data analysis. RESULTS: Seven themes and 32 subthemes were found: 1) understanding myself through mutual observation: self-discovery, self-acceptance, self-differentiation, career choices, breaking an addictive habit; 2) healing emotional wounds: trust building, self-closure, recognition of emotional wounds, peaceful mind; 3) being honest with my emotions: understanding addicts, expression of emotions, attitudes about confrontation, confronting others: 4) expressing myself: time management, expression of thanks, I-message, behavior modification, taking a stand; 5) balancing responsibility: attitudes about leaders and work, sharing work, supplementing, sharing opinions; 6) becoming interested in others: understanding family members, recognition of differences, asking about concerns of others, asking for forgiveness, conversation with family members ; 7) becoming interested in the community: attitudes about community, keeping rules, role model, active participation. CONCLUSION: These results show that a therapeutic community can be effective in changing participants' inner selves and behaviors.
Behavior Therapy ; Career Choice ; Drug Users ; Focus Groups ; Forgiveness ; Humans ; Statistics as Topic ; Therapeutic Community* ; Time Management ; Wounds and Injuries

OBJECTIVE: To investigate the relationship between minimum contralateral masking level (MCML) and pure tone threshold of the masking ears by the same frequency tone masking test. METHODS: The pure tone thresholds of 30 subjects (60 ears) were measured by pure tone audiometry and MCML was obtained by means of the same frequency tone masking test. RESULTS: When the stimulus was at the threshold of masked ears, the differences between MCML and pure tone threshold of masking ears were among 0-30 dBHL. 82.4 percent of results showed the differences not higher than 10 dBHL, 97.1 percent of results showed the differences not higher than 15 dBHL. When the stimulus was at 10 dBHL above the threshold of masked ears, the differences between MCML and pure tone threshold of masking ears were among 0-35 dBHL. 90.5 percent of results showed the differences not higher than 25 dBHL, 98.1 percent of results showed the differences not higher than 30 dBHL. CONCLUSION The real thresholds can be deduced correctly by the same frequency tone masking test.
Acoustic Stimulation/methods* ; Adult ; Audiometry, Pure-Tone/methods* ; Auditory Perception/physiology* ; Auditory Threshold ; Female ; Forensic Medicine/methods* ; Hearing Tests/methods* ; Humans ; Male ; Perceptual Masking

No abstract available.
Career Choice* ; Humans