Secret History: Return of the Black Death Channel 4, 7-8pm In 1348 the Black Death swept through London, killing people within days of the appearance of their first symptoms. Exactly how many died, and why, has long been a mystery. This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale. And they ask, what might be coming next?

Medscape

해외산업간호정보 - 미국 산업안전보건연구원(National Institute for Occupational Safety and Health) 소개

Experiments in hearing

This paper summarizes twenty studies, published since 1989, that have measured experimentally the relationship between speech recognition in noise and some aspect of cognition, using statistical techniques such as correlation or factor analysis. The results demonstrate that there is a link, but it is secondary to the predictive effects of hearing loss, and it is somewhat mixed across study. No one cognitive test always gave a significant result, but measures of working memory (especially reading span) were mostly effective, whereas measures of general ability, such as IQ, were mostly ineffective. Some of the studies included aided listening, and two reported the benefits from aided listening: again mixed results were found, and in some circumstances cognition was a useful predictor of hearing-aid benefit.

Are individual differences in speech reception related to individual differences in cognitive ability? A survey of twenty experimental studies with normal and hearing-impaired adults

Foundations of modern auditory theory

One of the frequently quoted reasons for the rejection of hearing aids is amplification of background noise The relationship between hearing aid use and toleration of background noise was assessed

Toleration of background noises: relationship with patterns of hearing aid use by elderly persons.

Two effects of reverberation on the identification of consonants were evaluated for ten normal‐hearing subjects: (1) the overlap of energy of a preceding consonant on the following consonant, called ‘‘overlap‐masking’’; and (2) the internal temporal smearing of energy within each consonant, called ‘‘self‐masking.’’ The stimuli were eight consonants /p,t,k,f,m,n,l,w/. The consonants were spoken in /s–at/ context (experiment 1) and generated by a speech synthesizer in /s–at/ and /–at/ contexts (experiment 2). In both experiments, identification of consonants was tested in four conditions: (1) quiet, without degradations; (2) with a babble of voices; (3) with noise that was shaped like either natural or synthetic /s/ for the two experiments, respectively; and (4) with room reverberation. The results for the natural and synthetic syllables indicated that the effect of reverberation on identification of consonants following /s/ was not comparable to masking by either the /s/‐spectrum‐shaped noise or the babble. In addition, the results for the synthetic syllables indicated that most of the errors in reverberation for the /s–at/ context were similar to a sum of errors in two conditions: (1) with /s/‐shaped noise causing overlap masking; and (2) with reverberation causing self‐masking within each consonant.

Reverberant overlap‐ and self‐masking in consonant identification

Cognitive slowing that accompanies aging may be reflected in temporal aspects of auditory processing. The purpose of this study was to investigate the effects of age, type of test, and rate of spee...

Effects of age, speech rate, and type of test on temporal auditory processing.

: Humans hear through air and bone conduction pathways. Both pathways can be used to transmit sound to a listener and from a talker although traditionally, the air conduction pathway has been used. Communication through bone conduction is a feasible alternative to air conduction reception and transmission and provides benefits to the user that an air conduction system cannot provide. This report combines results of an extensive literature review of the anatomy and physiology of human hearing, theories behind the mechanisms of bone conduction transmission, devices for use in bone conduction transmission, and the use of the bone conduction pathway for communication. Bone conduction for the transmission of communication is effective and feasible for Soldiers because it provides a means of providing radio communication in combination with hearing protection devices.

/pdf/bone-conduction-anatomy-physiology-and-communication-qe7lba9515.pdf

Bone Conduction: Anatomy, Physiology, and Communication

The goal of the present study was to investigate the human factors issues related to acoustic beacons used for auditory navigation. Specific issues addressed were: (1) the effect of various beacon characteristics on human accuracy in turning toward the direction of the acoustic beacon; (2) the difference between real and virtual environments on human accuracy in turning toward the acoustic beacon; and (3) the perceived sound quality of various acoustic beacons. Three experiments were conducted in which acoustic beacons were presented in a background of 80 dBA pink noise. Results of the localization tasks revealed that (a) presentation mode (continuous versus pulsed beacon sound) did not affect the overall localization accuracy or number of front-back confusion errors; and (b) the type of acoustic beacon affected the size of localization error. Results of the sound quality assessment indicated that listeners had definite preferences regarding the type of sound being used as a beacon, with (a) non-speech beacons preferred over speech beacons, (b) a beacon repetition rate of 1.1 rps preferred over either the 0.7 or 2.5 rps rates, and (c) a continuous operation of a beacon preferred over a pulsed operation. Finally, sound quality ratings and localization errors were highly negatively correlated. This finding demonstrates the usefulness and practical values of sound quality judgements for audio display design and evaluation.

Tomasz Letowski

Papers

Toleration of background noises: relationship with patterns of hearing aid use by elderly persons.

Reverberant overlap‐ and self‐masking in consonant identification

Effects of age, speech rate, and type of test on temporal auditory processing.

Bone Conduction: Anatomy, Physiology, and Communication

Evaluation of acoustic beacon characteristics for navigation tasks.