Wear and Airborne Noise Interdependency at Asperitical Level: Analytical Modelling and Experimental Validation

Generation of wear and airborne sound is inevitable during friction processes. Previously, the relationship between the wear and the sound has only been determined experimentally. Analytical models do exist, but they remain rare and do not fully account for the wear and the airborne sound generation especially at the asperitical level. This model attempts to fill the gap by providing a quantifiable relationship at an asperitical level between the wear generated and the sound emitted in a simple pin-on-disc setup. The model was validated for three materials (iron, mild steel, and aluminium T351) under two loads (10 N and 20 N) at 300 RPM. The theoretical model agrees with the experimental results with a varying error of 10 to 15% error in iron and aluminium. However, a larger error is observed in the case of mild steel. The model could be refined to improve the accuracy as it assumes point impacts on the asperities where a distributed impact would be more suitable. Furthermore, the pin is assumed a single asperity to simplify the model at the expense of accuracy. Overall, the experimental results are in good correlation with the theoretical results and this model provides the first step in quantifying wear using only the recorded sound pressure.

Covering Nasometer Microphones with Plastic Wrap for Infection Control Increases Retest Variability of Nasalance Scores

The Nasometer is a popular instrument for the acoustic assessment of nasality. In light of the currently ongoing COVID-19 global pandemic, clinicians may have wondered about the infection control procedures for the Nasometer. The current research investigated whether nasalance scores are affected if the Nasometer 6450 microphone casings are covered with a material such as rolled polyvinyl chloride household wrap. For the experiment, pre-recorded sound files from two speakers were played back through a set of small loudspeakers. Nasalance scores from two baselines and three wrap cover conditions were compared. While there was no statistically significant condition effect in a repeated-measures analysis of variance, the within-condition cumulative differences in nasalance scores were 2 for the initial baseline, 42 for wrap cover 1, 24 for wrap cover 2, 78 for wrap cover 3, and 8 for the final baseline. Mean differences between the wrap cover and the baseline conditions were 8.2 to 15.3 times larger, and cumulative differences were 8.3 to 16.6 times larger than between the two baselines. Based on the higher cumulative and mean differences observed, clinicians should not cover Nasometer microphones with household wrap as this increases variability of nasalance scores. Since there is evidence that the COVID-19 virus can survive for some time on metal surfaces, clinicians should be mindful of the fact that the Nasometer microphone housings can only be cleaned superficially and should be handled with gloves to minimize any possible risk of touch transfer of pathogens to the next speaker or the clinician.

Listening practice for learners of English: towards an intelligent tutoring system

We develop a web-application for practice of listening skills by learners of English, which allows users to listen to pre-recorded sound-files and respond to multiple-choice questions. They receive feedback as to the accuracy of their responses, and they are navigated through the set of items in one of two ways according to the group they are randomly assigned to. Members of a control group are guided from one item to the next depending on success or failure with each new item, and the difficulty ratings of the remaining items. For the experiment group, item selection is made in an adaptive fashion: selecting items through automatic predictions based on individual performance and observations of other students’ interactions with the platform, as well as known item attributes obtained through tagging. Based on the cognitive literature, we also provide listeners with the option of controlling the speed of presentation of the listening items.

Shopgirls as Consumers: Selling Popular Music in 1920s Australia

The mid-1920s were boom years for the Australian gramophone trade. The most prominent multinational record companies had established local branches, and a handful of new factories produced millions of records for sale on the local market. Department stores joined an established network of music traders in retailing these cultural products. This article explores the labour of women involved in the retail sale of gramophone records in Melbourne. Selling recorded sound animated a charged rhetoric of musical meliorism, class and taste, according to which the value of the product was determined by the supposed musical quality thereof. Australian saleswomen or “shopgirls” were required to perform evidence of their modernity in the commercial encounter. I propose that conceiving of record saleswomen as simultaneously sellers and consumers provides valuable insight into the entangled nature of capitalism and culture in the realm of Australian music. This exploration of the process of commercialisation of recorded music illuminates the connection between labour and culture, leisure and society in colonial modernity.

Noise and Spatial Configuration in Biskra, Algeria—A Space Syntax Approach to Understand the Built Environment for Visually Impaired People

This contribution investigates the correlation between street noise levels and the spatial configuration of the street network in four different types of neighbourhoods in the Algerian city of Biskra. Space syntax methods are used to analyse spatial relationships, where accessibility, intelligibility, and legibility of urban spaces can be evaluated. The degree of spatial integration is used as an accessibility indicator and is correlated with recorded noise level data at 154 points from the selected neighbourhoods. As the results show, there are strong correlations between spatial integration and recorded sound pressures on streets and roads in colonial and unplanned neighbourhoods. The reason is that these types of neighbourhoods have a street network with high correlations between street connectivity and global spatial integration. There are weak correlations between connectivity and global spatial integration throughout the modern planned neighbourhood, which again affects the correlation between noise and space. The experiment shows that space syntax methods have the potential to predict degrees of accessibility and orientability for people with visual impairments in urban planning.

Audio Database for TIAGo Service Robot

In this paper we present an updated version of the audio database acquired by the TIAGo service robot and by the simulated TIAGo service robot. To the initial database which consists in 1380 audio signals we have added 1920 more acoustic signals. The audio database consists now in 3300 isolated audio events corresponding to 110 classes. All the recorded sound events correspond to the indoor environment, and they are spread into five different scenarios: kitchen, room, appliances, voice and non-verbal. The audio database is intended to be used in order to identify indoor events based on audio signature, especially when elderly or chronically ill people live alone.

Inventing the recording

This chapter introduces the gabinetes fonográficos that appeared after the introduction of the Spring Motor Phonograph, Edison Home Phonograph, and Edison Standard Phonograph between 1896 and 1898; these were small recording labels which recorded their own wax cylinders employing local musicians and sold them directly to their customers, operating often precariously or for a limited amount of time. The chapter then discusses the gabinetes that were active between 1896 and 1905 in Madrid, then the main center of the nascent Spanish recording industry. The chapter examines how the Madrid gabinetes built upon ways of listening developed earlier in the decade to transform recorded sound into a commodity, and how, in doing so, they drew upon regeneracionista discourses concerning science, technology, modernity, and national identity.

Modelling the Microphone-Related Timbral Brightness of Recorded Signals

Brightness is one of the most common timbral descriptors used for searching audio databases, and is also the timbral attribute of recorded sound that is most affected by microphone choice, making a brightness prediction model desirable for automatic metadata generation. A model, sensitive to microphone-related as well as source-related brightness, was developed based on a novel combination of the spectral centroid and the ratio of the total magnitude of the signal above 500 Hz to that of the full signal. This model performed well on training data (r = 0.922). Validating it on new data showed a slight gradient error but good linear correlation across source types and overall (r = 0.955). On both training and validation data, the new model out-performed metrics previously used for brightness prediction.

Recognition System Of The Al Qur’an Surah Al-Falaq Verse 1-5 Through Voice Using Ada-Boost

In everyday life, it is not uncommon when we hear the sound of chanting the holy verses of the Al Al Qur’an which are read in mosques before prayer time or in other conditions we seem interested in knowing what Surah and which verse is being recited. This is due to the love of Muslims themselves for the Al Qur’an but not all Muslims memorize the entire contents of the Al Qur’an . Based on the limitations and the magnitude of curiosity about Surah and Verse information, the writer is interested in developing a computer system that can recognize and provide information on the recited Surah and Verse. Advances in computer technology not only make it easier for humans to carry out activities. One of the human intelligences that are planted into computer technology is to recognize the verses of the Al Al Qur’an Surah Al-Falaq through voice. Ada-Boost method is one method to identify or recognize voice classification, and by using this method the success rate in recognizing verse numbers reaches 72%. This system can only recognize the number of verses of the Al Al Qur’an Surah Al-Falaq, recorded sound files with the .wav file extension and built using the Delphi programming language.

Jack Ellitt as Director: Documentary Films of the 1940s

This article examines the work of the film-maker and composer Jack Ellitt (1902–2001) who remains something of an enigmatic and marginal figure in historical accounts of British documentary cinema. Research on Ellitt has so far focused on two key aspects of his life and career: firstly, his association with the New Zealand-born film-maker and artist Len Lye, and secondly, his pioneering work as a composer of electro-acoustic music. However, little research been undertaken on the work that he produced during the three decades he spent working as a documentary director in the British film industry, beginning in the early 1940s and ending with his retirement in the 1970s. He was a member of the remarkable generation of film-makers associated with the British documentary movement, and a composer whose radical experiments with recorded sound might well have secured him a more prominent place in the history of experimental music than is currently the case. Focusing on films made by Ellitt during the 1940s, the primary aim of this article is to offer a chronological appraisal of his early work as documentary director, while also considering what new perspectives this group of films might offer on his earlier creative collaboration with Lye, and the extent to which his radical experiments in electro-acoustic composition may have influenced the use of sound within the films he directed.