Nigel Holt - Profile on Academia.edu (original) (raw)
Papers by Nigel Holt
Acta Acustica United With Acustica, Nov 1, 2014
Noise is an unavoidable component of motorcycling. The noise sources are varied, and include the ... more Noise is an unavoidable component of motorcycling. The noise sources are varied, and include the helmet itself which also filters the noise passing through it. Here helmet noise transmission characteristics have been analyzed using insertion loss measurements and loudness matching in a behavioural study. Results demonstrate the action of the helmet as a spectral filter and confirm previously published data showing attenuation in the frequency range above 500Hz. Highlighted here for the first time is an amplification of noise below 500Hz. The loudness matching task data allowed the generation of equiloudness functions which show the effect of the helmet on riders' perceptions of loudness. The generated curves are here compared to the relevant international standard (ISO226) and show that loudness was strongly influenced by the helmet. The noise experienced by a motorcycle rider on a 30 minute journey can result in a temporary hearing threshold shift of over 15dB. Due to the filtering characteristics of the helmet this threshold shift is highly frequency dependent. To quantify the frequency dependence of the resulting temporary hearing threshold shift pure tone audiometry was conducted before and after exposure to white noise, with and without a helmet in a laboratory setting and after on-road noise exposure. The difference is discussed in the framework of the filtering characteristics of the helmet.
Practical: What do you Think? Attitude Research
Practical: Head Size and Intelligence
Lateralization of nonspeech audio‐visual stimulus combinations
Journal of the Acoustical Society of America, Apr 1, 1996
Ability to lateralize stimuli was measured in eight normally hearing subjects. In experiment 1 au... more Ability to lateralize stimuli was measured in eight normally hearing subjects. In experiment 1 auditory or visual stimuli were presented. Subjects responded with an auditory or visual pointer in conditions where stimulus and response modalities were the same (uni-modal) or different (cross-modal). A linear relationship was found between the position of the target stimuli and the perceived lateral position, establishing the correspondence between auditorily and visually presented positions, consistent with Yost [J. Acoust. Soc. Am. 70, 397–409 (1981)]. Mean judgments of linear position were independent of stimulus or response modality. In experiment 2 subjects were presented with bi-modal audio-visual stimuli with spatially and temporally correspondent modal components and subjects responded with an auditory pointer. Mean judgments of position were similar to those in experiment 1 but standard deviations were significantly smaller for the bi-modal stimuli relative to uni-modal stimuli. Experiments 3 and 4 involved manipulations of the spatial or temporal relationship between modal components of bi-modal stimuli. Whereas the relative importance of the visual modality was confirmed [Colavita, Percept. Psychophys. 15(2), 409–412 (1974)] the results of both experiments indicated that perception of the location of an audio-visual stimulus is influenced by information conveyed in both modalities. [Work supported by UKBBSRC.]
Research with People: Theory, Plans and Practicals
Abstract How do you measure human behavior? All of us observe human behavior everyday, but indivi... more Abstract How do you measure human behavior? All of us observe human behavior everyday, but individual habits can make large research studies difficult to design and conduct. In this accessible introductory textbook, Holt and Walker survey a wide range of ...
A2 Psychology 2008 AQA A Specification: The Student's Textbook
Targeted Mental Health in Schools Project Self-Harm: Supporting Students at Risk from Self-Harming Behaviours
Practical: Too Many Cooks or Not Enough Heads?
Effects of a Complex Reflection on Vowel Identification
Acta Acustica United With Acustica, May 1, 2000
Page 1. 532 © S. Hirzel Verlag . EAA ACUSTICA . acta acustica Vo!. H6 (2000) 532-542 Effects of a... more Page 1. 532 © S. Hirzel Verlag . EAA ACUSTICA . acta acustica Vo!. H6 (2000) 532-542 Effects of a Complex Reflection on Vowel Identification Anthony J. Watkins, Nigel 1. Holt Department of Psychology, The University of Reading, Reading RG6 6AL, UK ...
Journal of the Acoustical Society of America, Sep 1, 2013
The noise source mechanisms involved in motorcycling include various aerodynamic sources and engi... more The noise source mechanisms involved in motorcycling include various aerodynamic sources and engine noise. The problem of noise source identification requires extensive data acquisition of a type and level that have not previously been applied. Data acquisition on track and on road are problematic due to rider safety constraints and the portability of appropriate instrumentation. One way to address this problem is the use of data from wind tunnel tests. The validity of these measure ments for noise source identification must first be demonstrated. In order to achieve this extensive wind tunnel tests have been conducted and compared with the results from on-track measurements. Sound pressure levels as a function of speed were compared between on track and wind tunnel tests and were found to be comparable. Spectral conditioning techniques were applied to separate engine and wind tunnel noise from aerodynamic noise and showed that the aerodynamic components were equivalent in both cases. The spectral conditioning of on-track data showed that the contribution of engine noise to the overall noise is a function of speed and is more significant than had previously been thought. These procedures form a basis for accurate experimental measurements of motor cycle noise. V 2013 Acoustical Society of America.
A2 Psychology: The Study Guide
Spectral filtering characteristics of a motorcycle helmet
Journal of the Acoustical Society of America, Apr 1, 2011
Noise transmission characteristics of a motorcycle helmet have been analyzed using a combination ... more Noise transmission characteristics of a motorcycle helmet have been analyzed using a combination of insertion loss measurements and loudness matching in a behavioral study. Results demonstrate the action of the motorcycle helmet as a spectral filter. The insertion loss measurements confirm previously published data showing attenuation in the frequency range above 500 Hz. A further feature, the significance of which is addressed and highlighted here for the first time, is an amplification of noise below 500 Hz. In short, the helmet acts as a frequency dependent filter on the input to the human auditory system. Data from the matching task were used to generate equiloudness curves which show the effect of the helmet on riders’ perceptions of loudness. The generated curves were compared to the international standards (ISO226). The character of the equal loudness curves was strongly influenced by the helmet. This difference is discussed in the framework of the filtering characteristics of the helmet.
The sources and effects of noise exposure in motorcyling
Journal of the Acoustical Society of America, Apr 1, 2011
We report on the Bath Motorcycle Collaboration, an interdisciplinary collaborative research effor... more We report on the Bath Motorcycle Collaboration, an interdisciplinary collaborative research effort involving the Departments of Mechanical Engineering and Psychology at the University of Bath and Bath Spa University in the United Kingdom. The group has taken a broad approach to the problem of noise in motorcycling, examining its sources, transmission, and effects. Noise-induced hearing loss is a problem which can affect professional riders and racers as well as leisure riders and commuters. To study the problem, extensive wind tunnel tests have been conducted to provide detailed aerodynamic measurements and flow visualization around the helmet. These results have then been compared with and validated using on-track data covering realistic riding conditions. Insertion loss measurements combined with loudness matching tasks on groups of volunteers have been used to investigate the process of noise transmission through the head/helmet system. Hearing threshold shift measurements have been conducted to quantify the effects of this type of noise exposure on riders. This comprehensive approach has yielded valuable information for rider safety and has helped identify the research questions which will lead to a proper understanding of this important health and safety issue.
The effects of windscreen flow on noise in motorcycle helmets
Journal of the Acoustical Society of America, Apr 1, 2011
Vortex shedding from a motorcycle windscreen results in three flow regions into which the helmet ... more Vortex shedding from a motorcycle windscreen results in three flow regions into which the helmet of the rider may be immersed. First, the helmet may be fully in the free stream. Second, the helmet may be directly in the path of vortex shedding from the windscreen. Third, the helmet may be beneath the vortex shedding and shielded from the free stream by the windscreen. On-track tests were conducted and show a difference in sound pressure level of over 10 dB and a change in spectral content for different riding positions and helmet angle. Similar tests were then conducted in a wind tunnel, where simultaneous microphone and flow visualisation measurements allowed the identification and investigation of each flow region under controlled conditions. The contribution of vortex shedding to the noise was assessed using a combination of wavelet analysis and conditional averaging to identify intermittent structures.
Motorcycle helmets and the frequency dependence of temporary hearing threshold shift
Journal of the Acoustical Society of America, Apr 1, 2011
Temporary hearing threshold shifts (THTSs) as a result of exposure to noise vary as a function of... more Temporary hearing threshold shifts (THTSs) as a result of exposure to noise vary as a function of the noise’s spectral content. However, to date THTS has been measured and predicted in a way that does not take account of frequency variation—most notably in standards such as British Standard 5330. We therefore carried out pure-tone audiometry on participants before and after exposure to white noise in order to quantify the frequency dependence of the THTS. Moreover, as this research group has previously shown that motorcycle helmets act as spectral filters, attenuating noise in the region above 500 Hz and amplifying noise in the regions below 500 Hz; this was done both with and without a motorcycle helmet. As our previous findings would suggest, the pattern of threshold shift is a function of the filter characteristics of the helmet, including an increased sensitivity at higher frequencies. There was also greater than expected reduction in sensitivity at frequencies where the helmet amplifies incident noise. The results indicate an acoustic effect of helmets which has not previously been reported.
As Level Psychology: The Study Guide
Who will you Study? Samples and Populations
Think Critically: Don’t Believe Everything you Read
The Problem with People: Variation and Hypothesis Testing
Acta Acustica United With Acustica, Nov 1, 2014
Noise is an unavoidable component of motorcycling. The noise sources are varied, and include the ... more Noise is an unavoidable component of motorcycling. The noise sources are varied, and include the helmet itself which also filters the noise passing through it. Here helmet noise transmission characteristics have been analyzed using insertion loss measurements and loudness matching in a behavioural study. Results demonstrate the action of the helmet as a spectral filter and confirm previously published data showing attenuation in the frequency range above 500Hz. Highlighted here for the first time is an amplification of noise below 500Hz. The loudness matching task data allowed the generation of equiloudness functions which show the effect of the helmet on riders' perceptions of loudness. The generated curves are here compared to the relevant international standard (ISO226) and show that loudness was strongly influenced by the helmet. The noise experienced by a motorcycle rider on a 30 minute journey can result in a temporary hearing threshold shift of over 15dB. Due to the filtering characteristics of the helmet this threshold shift is highly frequency dependent. To quantify the frequency dependence of the resulting temporary hearing threshold shift pure tone audiometry was conducted before and after exposure to white noise, with and without a helmet in a laboratory setting and after on-road noise exposure. The difference is discussed in the framework of the filtering characteristics of the helmet.
Practical: What do you Think? Attitude Research
Practical: Head Size and Intelligence
Lateralization of nonspeech audio‐visual stimulus combinations
Journal of the Acoustical Society of America, Apr 1, 1996
Ability to lateralize stimuli was measured in eight normally hearing subjects. In experiment 1 au... more Ability to lateralize stimuli was measured in eight normally hearing subjects. In experiment 1 auditory or visual stimuli were presented. Subjects responded with an auditory or visual pointer in conditions where stimulus and response modalities were the same (uni-modal) or different (cross-modal). A linear relationship was found between the position of the target stimuli and the perceived lateral position, establishing the correspondence between auditorily and visually presented positions, consistent with Yost [J. Acoust. Soc. Am. 70, 397–409 (1981)]. Mean judgments of linear position were independent of stimulus or response modality. In experiment 2 subjects were presented with bi-modal audio-visual stimuli with spatially and temporally correspondent modal components and subjects responded with an auditory pointer. Mean judgments of position were similar to those in experiment 1 but standard deviations were significantly smaller for the bi-modal stimuli relative to uni-modal stimuli. Experiments 3 and 4 involved manipulations of the spatial or temporal relationship between modal components of bi-modal stimuli. Whereas the relative importance of the visual modality was confirmed [Colavita, Percept. Psychophys. 15(2), 409–412 (1974)] the results of both experiments indicated that perception of the location of an audio-visual stimulus is influenced by information conveyed in both modalities. [Work supported by UKBBSRC.]
Research with People: Theory, Plans and Practicals
Abstract How do you measure human behavior? All of us observe human behavior everyday, but indivi... more Abstract How do you measure human behavior? All of us observe human behavior everyday, but individual habits can make large research studies difficult to design and conduct. In this accessible introductory textbook, Holt and Walker survey a wide range of ...
A2 Psychology 2008 AQA A Specification: The Student's Textbook
Targeted Mental Health in Schools Project Self-Harm: Supporting Students at Risk from Self-Harming Behaviours
Practical: Too Many Cooks or Not Enough Heads?
Effects of a Complex Reflection on Vowel Identification
Acta Acustica United With Acustica, May 1, 2000
Page 1. 532 © S. Hirzel Verlag . EAA ACUSTICA . acta acustica Vo!. H6 (2000) 532-542 Effects of a... more Page 1. 532 © S. Hirzel Verlag . EAA ACUSTICA . acta acustica Vo!. H6 (2000) 532-542 Effects of a Complex Reflection on Vowel Identification Anthony J. Watkins, Nigel 1. Holt Department of Psychology, The University of Reading, Reading RG6 6AL, UK ...
Journal of the Acoustical Society of America, Sep 1, 2013
The noise source mechanisms involved in motorcycling include various aerodynamic sources and engi... more The noise source mechanisms involved in motorcycling include various aerodynamic sources and engine noise. The problem of noise source identification requires extensive data acquisition of a type and level that have not previously been applied. Data acquisition on track and on road are problematic due to rider safety constraints and the portability of appropriate instrumentation. One way to address this problem is the use of data from wind tunnel tests. The validity of these measure ments for noise source identification must first be demonstrated. In order to achieve this extensive wind tunnel tests have been conducted and compared with the results from on-track measurements. Sound pressure levels as a function of speed were compared between on track and wind tunnel tests and were found to be comparable. Spectral conditioning techniques were applied to separate engine and wind tunnel noise from aerodynamic noise and showed that the aerodynamic components were equivalent in both cases. The spectral conditioning of on-track data showed that the contribution of engine noise to the overall noise is a function of speed and is more significant than had previously been thought. These procedures form a basis for accurate experimental measurements of motor cycle noise. V 2013 Acoustical Society of America.
A2 Psychology: The Study Guide
Spectral filtering characteristics of a motorcycle helmet
Journal of the Acoustical Society of America, Apr 1, 2011
Noise transmission characteristics of a motorcycle helmet have been analyzed using a combination ... more Noise transmission characteristics of a motorcycle helmet have been analyzed using a combination of insertion loss measurements and loudness matching in a behavioral study. Results demonstrate the action of the motorcycle helmet as a spectral filter. The insertion loss measurements confirm previously published data showing attenuation in the frequency range above 500 Hz. A further feature, the significance of which is addressed and highlighted here for the first time, is an amplification of noise below 500 Hz. In short, the helmet acts as a frequency dependent filter on the input to the human auditory system. Data from the matching task were used to generate equiloudness curves which show the effect of the helmet on riders’ perceptions of loudness. The generated curves were compared to the international standards (ISO226). The character of the equal loudness curves was strongly influenced by the helmet. This difference is discussed in the framework of the filtering characteristics of the helmet.
The sources and effects of noise exposure in motorcyling
Journal of the Acoustical Society of America, Apr 1, 2011
We report on the Bath Motorcycle Collaboration, an interdisciplinary collaborative research effor... more We report on the Bath Motorcycle Collaboration, an interdisciplinary collaborative research effort involving the Departments of Mechanical Engineering and Psychology at the University of Bath and Bath Spa University in the United Kingdom. The group has taken a broad approach to the problem of noise in motorcycling, examining its sources, transmission, and effects. Noise-induced hearing loss is a problem which can affect professional riders and racers as well as leisure riders and commuters. To study the problem, extensive wind tunnel tests have been conducted to provide detailed aerodynamic measurements and flow visualization around the helmet. These results have then been compared with and validated using on-track data covering realistic riding conditions. Insertion loss measurements combined with loudness matching tasks on groups of volunteers have been used to investigate the process of noise transmission through the head/helmet system. Hearing threshold shift measurements have been conducted to quantify the effects of this type of noise exposure on riders. This comprehensive approach has yielded valuable information for rider safety and has helped identify the research questions which will lead to a proper understanding of this important health and safety issue.
The effects of windscreen flow on noise in motorcycle helmets
Journal of the Acoustical Society of America, Apr 1, 2011
Vortex shedding from a motorcycle windscreen results in three flow regions into which the helmet ... more Vortex shedding from a motorcycle windscreen results in three flow regions into which the helmet of the rider may be immersed. First, the helmet may be fully in the free stream. Second, the helmet may be directly in the path of vortex shedding from the windscreen. Third, the helmet may be beneath the vortex shedding and shielded from the free stream by the windscreen. On-track tests were conducted and show a difference in sound pressure level of over 10 dB and a change in spectral content for different riding positions and helmet angle. Similar tests were then conducted in a wind tunnel, where simultaneous microphone and flow visualisation measurements allowed the identification and investigation of each flow region under controlled conditions. The contribution of vortex shedding to the noise was assessed using a combination of wavelet analysis and conditional averaging to identify intermittent structures.
Motorcycle helmets and the frequency dependence of temporary hearing threshold shift
Journal of the Acoustical Society of America, Apr 1, 2011
Temporary hearing threshold shifts (THTSs) as a result of exposure to noise vary as a function of... more Temporary hearing threshold shifts (THTSs) as a result of exposure to noise vary as a function of the noise’s spectral content. However, to date THTS has been measured and predicted in a way that does not take account of frequency variation—most notably in standards such as British Standard 5330. We therefore carried out pure-tone audiometry on participants before and after exposure to white noise in order to quantify the frequency dependence of the THTS. Moreover, as this research group has previously shown that motorcycle helmets act as spectral filters, attenuating noise in the region above 500 Hz and amplifying noise in the regions below 500 Hz; this was done both with and without a motorcycle helmet. As our previous findings would suggest, the pattern of threshold shift is a function of the filter characteristics of the helmet, including an increased sensitivity at higher frequencies. There was also greater than expected reduction in sensitivity at frequencies where the helmet amplifies incident noise. The results indicate an acoustic effect of helmets which has not previously been reported.
As Level Psychology: The Study Guide
Who will you Study? Samples and Populations
Think Critically: Don’t Believe Everything you Read
The Problem with People: Variation and Hypothesis Testing