Auditory power-law activation-avalanches exhibit a fundamental computational ground-state

The cochlea provides a biological information-processing paradigm that we only begin to under- stand in its full complexity. Our work reveals an interacting network of strongly nonlinear dynami- cal nodes, on which even simple sound input triggers subnetworks of activated elements that follow power-law size statistics ('avalanches'). From dynamical systems theory, power-law size distribu- tions relate to a fundamental ground-state of biological information processing. Learning destroys these power laws. These results strongly modify the models of mammalian sound processing and provide a novel methodological perspective for understanding how the brain processes information.Comment: Videos are not included, please ask author

Individual differences in the discrimination of novel speech sounds: effects of sex, temporal processing, musical and cognitive abilities

This study examined whether rapid temporal auditory processing, verbal working memory capacity, non-verbal intelligence, executive functioning, musical ability and prior foreign language experience predicted how well native English speakers (N = 120) discriminated Norwegian tonal and vowel contrasts as well as a non-speech analogue of the tonal contrast and a native vowel contrast presented over noise. Results confirmed a male advantage for temporal and tonal processing, and also revealed that temporal processing was associated with both non-verbal intelligence and speech processing. In contrast, effects of musical ability on non-native speech-sound processing and of inhibitory control on vowel discrimination were not mediated by temporal processing. These results suggest that individual differences in non-native speech-sound processing are to some extent determined by temporal auditory processing ability, in which males perform better, but are also determined by a host of other abilities that are deployed flexibly depending on the characteristics of the target sounds

Valley-projected edge modes observed in underwater sonic crystals

Recently, the topological physics in acoustics has been attracting much attention. However, all the studies are aimed to elastic or airborne sound systems. Realizing topological insulators for underwater sound is of great importance, since water is another crucial sound medium in addition to solid and air. Here we report an experimental study on the valley-projected edge states for underwater sound. The edge states are directly observed in our ultrasound scanning experiments, together with a solid evidence for the valley-selective excitation. The experimental data agree well with our numerical results. Prospective applications can be anticipated, such as for underwater sound signal processing and ocean noise control.Comment: 5 figure

Relationships between human auditory cortical structure and function

The human auditory cortex comprises multiple areas, largely distributed across the supratemporal plane, but the precise number and configuration of auditory areas and their functional significance have not yet been clearly established. In this paper, we discuss recent research concerning architectonic and functional organisation within the human auditory cortex, as well as architectonic and neurophysiological studies in non-human species, which can provide a broad conceptual framework for interpreting functional specialisation in humans. We review the pattern in human auditory cortex of the functional responses to various acoustic cues, such as frequency, pitch, sound level, temporal variation, motion and spatial location, and we discuss their correspondence to what is known about the organisation of the auditory cortex in other primates. There is some neuroimaging evidence of multiple tonotopically organised fields in humans and of functional specialisations of the fields in the processing of different sound features. It is thought that the primary area, on Heschl's gyrus, may have a larger involvement in processing basic sound features, such as frequency and level, and that posterior non-primary areas on the planum temporale may play a larger role in processing more spectrotemporally complex sounds. Ways in which current knowledge of auditory cortical organisation and different data analysis approaches may benefit future functional neuroimaging studies which seek to link auditory cortical structure and function are discussed

Medicare 1971: Changing Attitudes and Changing Legislation

Bone conduction (BC) is the way sound energy is transmitted by the skull bones to the cochlea causing a sound perception. Even if the BC sound transmission involves several pathways including sound pressure induced in the ear canal, inertial forces acting on the middle ear ossicles and cochlear fluids, alteration of the cochlear space, and pressure transmission through the 3rd window of the cochlea, the BC sound ultimately produces a wave motion on the basilar membrane similar to that of air-conducted sound. The efficiency of the BC stimulation is largely dependent on the skull bone where the skull acts as a rigid body at low frequencies and incorporates different types of wave transmission at higher frequencies. The interaural stimulation difference is determined by the difference between contralateral and ipsilateral BC sound transmission: the transcranial BC sound transmission. To benefit from binaural processing, the transcranial transmission should be low, while the same should be high when using BC hearing aids for unilateral deaf subjects. By appropriately positioning the stimulation, high or low transcranial transmission can be achieved.Original Publication: Stefan Stenfelt , Acoustic and physiologic aspects of bone conduction hearing, 2011, Advances in Oto-Rhino-Laryngology, (71), 10-21. http://dx.doi.org/10.1159/000323574 Copyright: S. Karger AG http://www.karger.com/</p

Auditory perception modulated by word reading

Theories of embodied cognition positing that sensorimotor areas are indispensable during language comprehension are supported by neuroimaging and behavioural studies. Among others, the auditory system has been suggested to be important for understanding sound-related words (visually presented) and the motor system for action-related words. In this behavioural study, using a sound detection task embedded in a lexical decision task, we show that in participants with high lexical decision performance sound verbs improve auditory perception. The amount of modulation was correlated with lexical decision performance. Our study provides convergent behavioural evidence of auditory cortex involvement in word processing, supporting the view of embodied language comprehension concerning the auditory domain