Rapid formation of robust auditory memories: Insights from noise

Before a natural sound can be recognized, an auditory signature of its source must be learned through experience. Here we used random waveforms to probe the formation of new memories for arbitrary complex sounds. A behavioral measure was designed, based on the detection of repetitions embedded in noises up to 4 s long. Unbeknownst to listeners, some noise samples reoccurred randomly throughout an experimental block. Results showed that repeated exposure induced learning for otherwise totally unpredictable and meaningless sounds. The learning was unsupervised and resilient to interference from other task-relevant noises. When memories were formed, they emerged rapidly, performance became abruptly near-perfect, and multiple noises were remembered for several weeks. The acoustic transformations to which recall was tolerant suggest that the learned features were local in time. We propose that rapid sensory plasticity could explain how the auditory brain creates useful memories from the ever-changing, but sometimes repeating, acoustical world. © 2010 Elsevier Inc.

Informational masking in young and elderly listeners for speech masked by simultaneous speech and noise

Three experiments measured the effects of age on informational masking of speech by competing speech. The experiments were designed to minimize the energetic contributions of the competing speech so that informational masking could be measured with no large corrections for energetic masking. Experiment 1 used a "speech-in-speech-in-noise" design, in which the competing speech was presented in noise at a signal-to-noise ratio (SNR) of -4 dB. This ensured that the noise primarily contributed the energetic masking but the competing speech contributed the informational masking. Equal amounts of informational masking (3 dB) were observed for young and elderly listeners, although less was found for hearing-impaired listeners. Experiment 2 tested a range of SNRs in this design and showed that informational masking increased with SNR up to about an SNR of -4 dB, but decreased thereafter. Experiment 3 further reduced the energetic contribution of the competing speech by filtering it into different frequency bands from the target speech. The elderly listeners again showed approximately the same amount of informational masking (4-5 dB), although some elderly listeners had particular difficulty understanding these stimuli in any condition. On the whole, these results suggest that young and elderly listeners were equally susceptible to informational masking. © 2009 Acoustical Society of America.

The detection of repetitions in noise before and after perceptual learning.

In noise repetition-detection tasks, listeners have to distinguish trials of continuously running noise from trials in which noise tokens are repeated in a cyclic manner. Recently, it has been shown that using the exact same noise token across several trials (“reference noise”) facilitates the detection of repetitions for this token [Agus et al. (2010). Neuron 66, 610–618]. This was attributed to perceptual learning. Here, the nature of the learning was investigated. In experiment 1, reference noise tokens were embedded in trials with or without cyclic presentation. Naïve listeners reported repetitions in both cases, thus responding to the reference noise even in the absence of an actual repetition. Experiment 2, with the same listeners, showed a similar pattern of results even after the design of the experiment was made explicit, ruling out a misunderstanding of the task. Finally, in experiment 3, listeners reported repetitions in trials containing the reference noise, even before ever hearing it presented cyclically. The results show that listeners were able to learn and recognize noise tokens in the absence of an immediate repetition. Moreover, the learning mandatorily interfered with listeners' ability to detect repetitions. It is concluded that salient perceptual changes accompany the learning of noise.

Noise Quartet

Performance at the International Computer Music Conference, University of Huddersfield (with Eric Lyon, Franziska Schroder & Steve Davis).

Environmental Aspects of Underground Construction and Exploration of Underground Structure – State of the Art

An underground work (such as a tunnel or a cavern) has many, well known, environmental qualities such as: no physical barriers crossing the land, less maintenance costs than an analogous surface structure, less expenses for heating and conditioning; a localized emission of noise, gas, dust during operation and, finally, a better protection against seismic actions.
It cannot be forgotten, anyway, that some negative environmental features are present such as, for example, : perturbation, pollution and drainage of the groundwater; settlements; disposal of waste rock.
In the paper the above mentioned concepts are discussed and analysed to give a global overview of all this aspects.

Multibody modelling of a TB31 and a TB32 crash test with vertical portable concrete barriers: model verification and sensitivity analysis.

In this article the multibody simulation software package MADYMO for analysing and optimizing occupant safety design was used to model crash tests for Normal Containment barriers in accordance with EN 1317. The verification process was carried out by simulating a TB31 and a TB32 crash test performed on vertical portable concrete barriers and by comparing the numerical results to those obtained experimentally. The same modelling approach was applied to both tests to evaluate the predictive capacity of the modelling at two different impact speeds. A sensitivity analysis of the vehicle stiffness was also carried out. The capacity to predict all of the principal EN1317 criteria was assessed for the first time: the acceleration severity index, the theoretical head impact velocity, the barrier working width and the vehicle exit box. Results showed a maximum error of 6% for the acceleration severity index and 21% for theoretical head impact velocity for the numerical simulation in comparison to the recorded data. The exit box position was predicted with a maximum error of 4°. For the working width, a large percentage difference was observed for test TB31 due to the small absolute value of the barrier deflection but the results were well within the limit value from the standard for both tests. The sensitivity analysis showed the robustness of the modelling with respect to contact stiffness increase of ±20% and ±40%. This is the first multibody model of portable concrete barriers that can reproduce not only the acceleration severity index but all the test criteria of EN 1317 and is therefore a valuable tool for new product development and for injury biomechanics research.

Reconciling Children's Policy and Children's Rights: Barriers to Effective Government Delivery

Countries which have ratified the United Nations Convention on the Rights of the Child, have committed to implementing its principles in law and policy. This article explores the challenges for securing children's rights through policy, drawing on a research project conducted for the Northern Ireland Commissioner for Children and Young People, which sought to identify barriers to effective government delivery for children and young people from the perspective of key stakeholders. The research concluded that, while some barriers (such as delay and availability of data) are not child-specific, they can be accentuated when children and young people are the main focus of policy development and more so when seeking to adopt a child rights-compliant approach to policy development and implementation. 

Rethinking Local Government Support for Youth Arts:The Case of NOISE South Dublin

Within Ireland, interest in strategically supporting young people’s participation in the arts has increased. Additionally, awareness of the Internet’s potential for promot- ing engagement with the arts has grown. Addressing national directives and local needs assessments, South Dublin County Council’s Arts Office initiated NOISE South Dublin (http://www.noisesouthdublin.com), an interactive Web site based on Australia Council’s NOISE project (http://www.noise.net), to promote the creative development of young people in the county. This article presents the practical chal- lenges and potential of youth arts Web-based programs for harnessing the creative engagement of youth. It concludes that the Internet is only useful if it expands online engagement offline.

The perspectives of ‘disengaged’ students in the 14–19 phase on motivations and barriers to learning within the contexts of institutions and classrooms

In addressing educational disengagement, government policy in England focuses primarily on raising the age of educational participation, promoting vocationalism and directing resources at the population of young people not engaged in any education, employment or training (NEETs). However, ‘disengagement’ is a more fluid and dynamic concept than policy allows for and is visible within a wide range of students, even those deemed to be engaged by their presence in education and educational settings. This paper presents students’ accounts of their educational experiences which suggest that the context of the classroom, student–teacher relationships, peer relationships and pedagogical methods used in classrooms are salient factors in understanding engagement.

The Reintegration of Sex Offenders: Barriers and Opportunities for Employment

The process of reintegration of offenders after release from prison, or during a community sentence, is a key aim of criminal justice policy. This article provides details from recent research that investigated the barriers and opportunities to employment for sex offenders. The authors describe the barriers that are faced by sex offenders and the anxieties that employers experience when employing sex offenders. The authors conclude that the approach taken by the State is less than reintegrative and serves to increase the barriers and reduce the opportunities for employment for sex offenders.