Effect of diurnal changes on dichotic listening in younger adults with normal hearing

Background:Diurnal changes can be defined as the time of the day over an individual's performance level for different activities that involve physical and mental tasks.Objective:The current study aimed to evaluate the effect of diurnal changes in scores obtained for the Dichotic Consonant-Vowel paradigm by young adults with normal hearing sensitivity.Method:Based on the‘Morningness-Eveningness questionnaire’given by Horne&Ostberg,the subjects were divided into moderately-morning,intermediate and moderately-evening categories.The Dichotic Consonant-Vowel tests were performed during morning and evening,and the right ear,left ear and double correct scores were compared between morning and evening for each category.Results:There was significant diurnal changes noted for moderately morning and evening categories,where morning-type individuals performed better during morning and evening-type individuals performed better during the evening.The scores of intermediate individuals remained unchanged between morning and evening test results.Conclusion:Diurnal change is a phenomenon associated with an individual's biological clock mechanism.Hence,attention and inhibitory controls aid them in carrying out tasks that require sufficient physical and mental efforts.The current study suggests that clinicians and researchers consider diurnal changes as an extraneous variable that could affect the reliability of the Dichotic Consonant-Vowel test results.

Development, and validation of non-speech dichotic listening test

Background:Classic dichotic listening tests using speech stimuli result in right ear advantage,due to the dominant crossed pathway for speech and language.It is presumed that similar crossed dominance could exist for non-speech stimuli too.Hence,this is an attempt to develop and validate the dichotic nonspeech test using environmental stimuli and explore the effect of focused attention on this test.Materials and method:Three lists of dichotic stimuli were created using these sounds with fifteen tokens in each list.Four professionals and non-professionals validated these materials.Normative estimation was obtained by administering the newly developed test on 70 adults and 70 children using a free-recall and forced-recall condition.Result:The results showed a significant difference between the left ear and right scores where the left ear score was better than the right,depicting left ear advantage(LEA)for free recall condition in both groups.In the forced recall condition,LEA was not seen;rather the mean score was significantly higher in the attended ear,irrespective of the stimuli presented to the right or left ear.The test-retest reliability in free recall was good in both the ears and moderate for forced right ear conditions.Conclusion:The novel test consistently showed LEA with good reliability and can be used to assess the hemispheric asymmetry in normal subjects and also in test batteries for the clinical population.

Design of Optimized Wavelet Packet Algorithm to Improve Perception of Sensorineural Hearing Impaired

A novel optimized wavelet packet algorithm is proposed to improve the perception of sensorineural hearing-impaired people. In this work, we have developed optimized wavelet packet along with, biorthogonal wavelet basis functions using MATLAB Code. Here, we have created eight bands based on auditory filters of quasi octave bandwidth. Evaluation was carried out by conducting listening tests on seven subjects with bilateral mild to severe sensorineural hearing loss. The speech material used for the listening test consisted of a set of fifteen nonsense syllables in VCV context. The test results show that the proposed algorithm improves the recognition score, speech quality and transmission of overall feature specifically over the unprocessed signal. The response time also reduces significantly.

The crisis of representation in the postmodern era: On Barry Levinson's film Wag the Dog

Barry Levinson's film Wag the Dog(1997) is concerned with the technological transformation of American culture in the postmodernism which is isomorphic with the media culture of American society in the late twentieth century. By exploring three dualities illustrated in the film,this paper aims to show the insecure and uncertain categories of these oppositions under the dominant phenomena of this period: the media,so as to bring about the public's ability to discern the postmodern world as well as a new ways of thinking and living.

Dependence of binaural loudness summation on interaural level difference and frequency for pure tones

Most of the existing loudness models are based on the diotic listening hypothesis,though human beings always hear in dichotic listening conditions.In this situation,the arithmetic mean of loudness at both ears is usually taken as the approximate value of overall perceived loudness,unaffected by the interaural level difference(ILD).The present work investigated the overall perceived loudness for pure tones in dichotic listening conditions through a subjective experiment.Two experimental procedures and systematic errors were investigated to prove the accuracy of the subjective test.The results showed that fluctuation was insignificant in the low frequency range,while apparent fluctuation of overall loudness could be observed at a high frequency.The overall loudness deviated from the arithmetic mean value as the ILD became larger.A revised model for overall loudness in dichotic listening conditions was proposed.The proposed model and experiment are consistent.