i++ School Newsletter

Week commencing 2 January 2012

Previous Newsletters

papers published

Professor Malcolm Hawksford has had a couple of papers published recently. 

"Perceptually-Motivated Objective Grading of Nonlinear Processing in Virtual-Bass Systems" with Nay Oo, Woon-Seng Gan. Abstract: Nonlinear devices (NLDs) can be used in bass-enhancement systems to create psychoacoustic-derived virtual-bass extension by synthesizing harmonics of a missing fun­damental. Problematically, such NLD-related distortions can also form perceptual distortion. Earlier studies reveal that although objective measurement scores quantify bass enhancement and harmonic distortion, there is weak correlation with subjective perception. An in-depth sub­jective study is presented on NLD-specific distortion linked to perception and bass-intensity enhancement and then extended to correlate the Rnonlin distortion model to subjective data. Nonlinear regression computes Rnonlin-equation coefficients to enable a metric for audibility of NLD-dependent distortion. Recommendations follow for NLD sets that achieve good bass performance with low perceived distortion.

"Wide-Area Psychoacoustic Correction for Problematic Room-Modes Using Nonlinear Bass Synthesis" with Adam Hill.  Abstract: Small room acoustics are characterized by a limited number of dominant low-frequency room-modes that result in wide spatio-pressure variations that traditional room correction systems may find elusive to correct over a broad listening area. A psychoacoustic-based methodology is proposed whereby signal components coincident only with problematic modes are filtered and substituted by virtual bass components to forge an illusion of the suppressed frequencies. Although this approach can constitute a standalone correction system, the impetus for development is for use within well-established correction methodologies. A scalable and hierarchical approach is studied using subjective evaluation to confirm uniform wide-area performance. Bass synthesis exploits parallel nonlinear and phase vocoder generators with outputs blended as a function of transient and steady-state signal content.

csee students get £1,000 scholarships

Three Year 1 CSEE students from north Essex have received a prestigious scholarship to support their studies.  They won Eliahou Dangoor scholarships worth £1,000.  The scholarships were established by philanthropist Dr Naim Dangoor to support the best students across the country to help them realise their potential, and are only open to students at Russell Group or 1994 Group universities.

phd successes

Ben Royall has passed his PhD after his viva in December.  The title of his thesis is GaInNAs / GaAs Multiple Quantum Well and n-i-p-i Solar Cells.  He was supervised by Prof Naci Balkan and his examiners were Prof Judy Rorison (Bristol) and Dr Nick Zakhleniuk (Essex). Congratulations to Dr Royall!

John Wilson has passed his PhD with editorial corrections only.  He was supervised by Palani Ramaswamy and his examiners were Francisco Sepulveda (Essex) and Damien Coyle (Ulster).
John was funded by an EPSRC Studentship and his work was on establishing a viable brain-computer interface (BCI) paradigm using steady state evoked potentials.  Using phase spectral information, which is usually discarded, John was able to design an advanced system that mainly alleviated the need for robust training periods while maintaining comparable performance.  His work (jointly with Plymouth) resulted in a successful trial with a locked-in patient that enabled music control through the BCI device (this work recently received wide national and international press coverage).  
John was also the recipient of the prestigious IET William James Award for this year.  This competitive award is presented to the student whose PhD research shows the most potential to contribute towards the development and improvement of the biomedical engineering field.  Many congratulations to John!

forthcoming seminars

The seminar programme for the Spring term will be available shortly.