To alleviate the conflict between audibility and distortion in the conventional loudness compensation method, an adaptive multichannel loudness compensation method is proposed for hearing aids. The linear and wide dyn...To alleviate the conflict between audibility and distortion in the conventional loudness compensation method, an adaptive multichannel loudness compensation method is proposed for hearing aids. The linear and wide dynamic range compression （WDRC） methods are alternately employed according to the dynamic range of the band-passed signal and the hearing range （HR） of the patient. To further reduce the distortion caused by the WDRC and improve the output signal to noise ratio （SNR） under noise conditions, an adaptive adjustment of the compression ratio is presented. Experimental results demonstrate that the output SNR of the proposed method in babble noise is improved by at least 1.73 dB compared to the WDRC compensation method, and the average speech intelligibility is improved by 6.0% and 5. 7%, respectively, compared to the linear and WDRC compensation methods.展开更多
The recent Standard ISO 226 concerning equal-loudness-level contours has been critically analysed. As a result, it is shown that the fitting and smoothing processes applied in the standard lead to parameter values def...The recent Standard ISO 226 concerning equal-loudness-level contours has been critically analysed. As a result, it is shown that the fitting and smoothing processes applied in the standard lead to parameter values defining equal-loudness-level contours that are not consistent with the chosen loudness function type. Serious mathematical and acoustical discrepancies have also been found that result in constant terms having an unnecessarily high numerical accuracy and a flawed phon definition, which leads to an erroneous loudness level representation. Therefore an extensive treatment of the logarithmic calculations (phon) of a loudness function is performed in this study. Finally, the author concludes that it would be desirable for the discrepancies in the standard (shown in the study) to be taken into account and corrected before publishing a new version of the standard.展开更多
A stationary loudness model has been built up on the basis of the former ISO 226: 1987 concerning equal-loudness-level contours. The loudness and loudness level expressions derived in the study include the same parame...A stationary loudness model has been built up on the basis of the former ISO 226: 1987 concerning equal-loudness-level contours. The loudness and loudness level expressions derived in the study include the same parameters as used when determining the equal-loudness-level contours of the former ISO standard. However, as an additional main idea, a loudness summation rule has been proposed in the study. Moreover, the loudness expressions have been normalised to give the same values for people who have a similar sense of hearing. It has also been found that the loudness expressions include basically two different weightings. The first weighting is a conservative frequency weighting in the domain of sound pressure level, and the second weighting consists of coefficients applied to the weighted sound pressure levels. The latter have the greatest effect on the very low-frequency range. Finally, the paper includes a new way to use the A-weighting which takes into account the compressed character of the equal-loudness-level contours at the low frequency range. This method remarkably transforms the character of the A-weighting as a measure for low-frequency environmental noise.展开更多
A relation of loudness to loudness just noticeable difference (JND) is derived based on signal detection theory and the hypothesis that loudness is the nerve spike count in the duration of T, and the spike rate distr...A relation of loudness to loudness just noticeable difference (JND) is derived based on signal detection theory and the hypothesis that loudness is the nerve spike count in the duration of T, and the spike rate distribution of stable tonal stimulus is a stable normal stochastic process. The relation suggests that ratio of loudness JND to loudness of tone is independent of intensity, which can explain well experimental results about the relation of intensity JND to intensity of tone, especially those that could not be explained before such as the Weber fraction hump at the moderate level and the near miss to Weber's law.展开更多
Loudness, one of the distinguishing characteristics in auditorium acoustics, has received less attention by acoustical consultants than other parameters up to the present. Due to the lack of an appropriate paramcter, ...Loudness, one of the distinguishing characteristics in auditorium acoustics, has received less attention by acoustical consultants than other parameters up to the present. Due to the lack of an appropriate paramcter, neither measurements in auditorium on this subject is practicable, nor prediction could be made during the design process. The frequently applied method is by means of the summation of the direct sound and the reverberant sound as the total sound level over the audience area. In fact, this is only suitable for predicting the sound level from a steady sound source and in the reverberant field, apparently not appropriate in practice either for acoustic design or for on-site measurement. Strength index G (Starkemass in Germany) (dB), proposed by Lehmann, as loudness criteria, might be a proper parameter. But,as the primary results from our investigation and from others as well, showed that the early reflections presented the main contribution to the perccived loudness, it is more reasonable to set a limit to the integrating time of index G, say 50 ms for speech and 80 ms for music, which have been commonly recognized as useful portion in 'definition' and 'clarity', instead of the infinitive integrating time as Lehmann proposed. Therefore, G50 and G80 are highly recommendedto be used as loudness criteria for speech and music in auditorium acoustics respectfully.展开更多
Most of the existing loudness models are based on the diotic listening hypothesis,though human beings always hear in dichotic listening conditions.In this situation,the arithmetic mean of loudness at both ears is usua...Most of the existing loudness models are based on the diotic listening hypothesis,though human beings always hear in dichotic listening conditions.In this situation,the arithmetic mean of loudness at both ears is usually taken as the approximate value of overall perceived loudness,unaffected by the interaural level difference(ILD).The present work investigated the overall perceived loudness for pure tones in dichotic listening conditions through a subjective experiment.Two experimental procedures and systematic errors were investigated to prove the accuracy of the subjective test.The results showed that fluctuation was insignificant in the low frequency range,while apparent fluctuation of overall loudness could be observed at a high frequency.The overall loudness deviated from the arithmetic mean value as the ILD became larger.A revised model for overall loudness in dichotic listening conditions was proposed.The proposed model and experiment are consistent.展开更多
Laughter is a universal language that brings people together.Among all forms of laughter,a loud laugh is particularly powerful.When someone laughs loudly,it can lift the mood of everyone nearby and create a joyful atm...Laughter is a universal language that brings people together.Among all forms of laughter,a loud laugh is particularly powerful.When someone laughs loudly,it can lift the mood of everyone nearby and create a joyful atmosphere.展开更多
The strength of a steady sound field in a hall depends on the direct sound levcl and the level of reflections from all boundaries. But for speech and music having impulsive characteristics, only the direct sound and t...The strength of a steady sound field in a hall depends on the direct sound levcl and the level of reflections from all boundaries. But for speech and music having impulsive characteristics, only the direct sound and the early reflections are effectivc to the perceived loudness to the listener according to the integrating abili ty of the ear. Therefore, a series of subjective comparison tests are carried out in an anechoic room, using recorded 'dry' speech as testing material are thus con ducted to investigate the contribution of short delayed echoes (early reflections) to thc loudness evaluation. Sound field consisting of primary sound and delayed echoes, single or multiple, are produced by electroacoustic means. Results show that the perceived louopess of the sound field is the function of the echo energy,angle of echo incidence and its temporal distribution. The law of the addition of energy to the echoes with a short delay is not applicable to multiple echoes as well as to a single echo after an interval exceeding 30-50 ms. In certain cases, they are much less than to be expected according to the said law.展开更多
The starting point of this study is the theory of tonal consonance by Plomp and Levelt. The major reference point is the theory of Critical Band and its use for evaluating consonance of simple tones. On the basis of s...The starting point of this study is the theory of tonal consonance by Plomp and Levelt. The major reference point is the theory of Critical Band and its use for evaluating consonance of simple tones. On the basis of such empirical criterion, our aim consists in providing a method of estimating the value of consonance of complex tones, by taking account not only of the number of harmonics, but also of the intensity of the partials which contribute to forming the tone. By introducing a specific algorithm, the level of consonance of a chord of complex tones is expressed in terms both of frequency differences and sound intensity of the partials. The results give rise to a series of considerations and applications, ranging from displaying the order of consonance of all intervals within the octave up to evaluating the hierarchy of chords in the frame of a musical scale.展开更多
This study examines the effect of speech level on intelligibility in different reverberation conditions, and explores the potential of loudness-based reverberation parameters proposed by Lee et al. [J. Acoust. Soc. Am...This study examines the effect of speech level on intelligibility in different reverberation conditions, and explores the potential of loudness-based reverberation parameters proposed by Lee et al. [J. Acoust. Soc. Am., 131(2), 1194-1205 (2012)] to explain the effect of speech level on intelligibility in various reverberation conditions. Listening experiments were performed with three speech levels (LAeq of 55 dB, 65 dB and 75 dB) and three reverberation conditions (T20 of 1.0 s, 1.9 s and 4.0 s), and subjects listened to speech stimuli through headphones. Collected subjective data were compared with two conventional speech intelligibility parameters (Speech Intelligibility Index and Speech Transmission Index) and two loudness-based reverberation parameters (EDTN and TN). Results reveal that the effect of speech level on intelligibility changes with a room’s reverberation conditions, and that increased level results in reduced intelligibility in highly reverberant conditions. EDTN and TN explain this finding better than do STI and SII, because they consider many psychoacoustic phenomena important for the modeling of the effect of speech level varying with reverberation.展开更多
On the basis of psychological acoustic theories and experiments, this paper proposes an acoustic model which is based on acoustic perceptual feature. Compared with the physiological acoustics based acoustic model, thi...On the basis of psychological acoustic theories and experiments, this paper proposes an acoustic model which is based on acoustic perceptual feature. Compared with the physiological acoustics based acoustic model, this model is more suitable to represent human’s perceptual features of continuous speech, so it is suitable for recognition of continuous speech.展开更多
A number of studies have been conducted on the improvement of the sound quality of electrical artificial laryngeal speech,the speech produced has been difficult to hear compared to a natural voice.For this reason,it i...A number of studies have been conducted on the improvement of the sound quality of electrical artificial laryngeal speech,the speech produced has been difficult to hear compared to a natural voice.For this reason,it is necessary to effectively improve the frequency characteristics of the input signal.In the present study,to improve the sound quality of vocalization using an electrical artificial larynx,first,a comparison of the frequency characteristics between the real and artificial voices was conducted,and three filters that can make the frequency characteristics of the artificial voice closer to those of a real voice were generated.Then,the influence of these filters on the quality of the artificial voice was investigated via physical measurement and a subjective evaluation experiment targeted at Japanese five vowels.It was found that the intelligibility of artificial/a/and/o/sounds was improved,whereas little improvement was observed in the case of/i/,/u/,and/e/.The obtained results confirmed the effect of optimizing the input signal into the vibration speaker and indicated areas for further improvement.展开更多
Ambisonics is a series of flexible spatial sound reproduction systems based on spatial harmonics decomposition of sound field.Traditional horizontal and spatial Ambisonics reconstruct horizontal and spatial sound fiel...Ambisonics is a series of flexible spatial sound reproduction systems based on spatial harmonics decomposition of sound field.Traditional horizontal and spatial Ambisonics reconstruct horizontal and spatial sound field with certain order of spatial harmonics,respectively.Both the Shannon-Nyquist spatial sampling frequency limit for accurately reconstructing sound field and the complexity of system increase with the increasing order of Ambisonics.Based on the fact that the horizontal localization resolution of human hearing is higher than vertical resolution,mixed-order Ambisonics(MOA)reconstructs horizontal sound field with higher order spatial harmonics,while reconstructs vertical sound field with lower order spatial harmonics,and thereby reaches a compromise between the perceptual performance and the complexity of system.For a given order horizontal Ambisoncis or MOA reproduction,the number of horizontal loudspeakers is flexible,providing that it exceeds some low limit.By using Moore’s revised loudness model,the present work analyzes the influence of the number of horizontal loudspeakers on timbre both in horizontal Ambisonics and MOA reproduction.The binaural loudness level spectra(BLLS)of Ambisoncis reproduction are calculated and then compared with those of target sound field.The results indicate that below the Shannon-Nyquist limit of spatial sampling,increasing the number of horizontal loudspeakers influence little on BLLS then timbre.Above the limit,however,the BLLS for Ambisoncis reproduction deviate from those of target sound field.The extent of deviation depends on both the direction of target sound field and the number of loudspeakers.Increasing the number of horizontal loudspeakers may increase the change of BLLS then timbre in some cases,but reduce the change in some other cases.For MOA,the influence of the number of horizontal loudspeakers on BLLS and timbre reduces when virtual source departs from horizontal plane to the high or low elevation.The subjective evaluation experiment also validates the analysis.展开更多
This paper makes comments on conflicts in a micro-story of 527 words,The Ray,written by American writer Ron Milner.The story,from a unique perspective of narration,attracts and strikes the reader as a loud protest ami...This paper makes comments on conflicts in a micro-story of 527 words,The Ray,written by American writer Ron Milner.The story,from a unique perspective of narration,attracts and strikes the reader as a loud protest amidst silence,against human beings' self-destructive abuse of nuclear technology and craziness of arms races during the cold war.The paper,from the historical,cultural,and religious contexts,presents an analysis of the hero's death and of the message the reader can draw from the story.展开更多
The aim of this study is to investigate the biological effects of ion beams on pollen. Pollen grains of Cedrus deodara were implanted with 30 keV nitrogen ion beams at doses ranging from 1 × 10^15 ions/cm^2 to 15...The aim of this study is to investigate the biological effects of ion beams on pollen. Pollen grains of Cedrus deodara were implanted with 30 keV nitrogen ion beams at doses ranging from 1 × 10^15 ions/cm^2 to 15 × 10^15 ions/cm^2. The effects of N^＋ implantation on the pollen exine substructure were examined using an atomic force microscope （AFM）, and the structure and morphology of pollen and pollen tubes were observed using a laser scanning confocal microscope （LSCM）. AFM observations distinctly revealed the erosion of the pollen exine caused by N^＋ implantation in the micrometer to nanometer range. Typical results showed that the erosion degree was linearly proportional to the ion dose. Pollen germination experiments in vitro indicated that N^＋ implantation within a certain dose range increased the rate of pollen germination. The main abnormal phenomena in pollen tubes were also analyzed. Our results suggest that low energy ion implantation with suitable energy and dosage can be used to break the pollen wall to induce a transfer of exogenous DNA into the pollen without any damage to the cytoplasm and nuclei of the pollen. The present study suggests that a combination of the method of ion-beam-induced gene transfer and the pollen-tube pathway method （PTPW） would be a new plant transformation method.展开更多
Humor is needed universally. The ability to make jokes or to appreciate humor is both necessary for living a happy or smooth life. Different nations have different humors. The paper is to analyze the definition of hum...Humor is needed universally. The ability to make jokes or to appreciate humor is both necessary for living a happy or smooth life. Different nations have different humors. The paper is to analyze the definition of humor, the difference between British and American humor, and take James Thurber＇s stories to show the typical American humor. The English appear to be deeply serious people. English humor is more conserved, subtle, and silent. The British are known for their sense of humor. However, it is often difficult for foreigners to understand their jokes. The key to understanding British humor is to know that the British often use ＂understatement＂. American humor tends to be more ＂obvious＂ and less oblique, and can sometimes be considered by other English speaking cultures to be over the top and ridiculous.展开更多
The continued popularity of reality television, and the release of the recent HBO film Cinema Verite--about the production of the first ＂reality show,＂ An American Family （1973） --has resulted in renewed interest ...The continued popularity of reality television, and the release of the recent HBO film Cinema Verite--about the production of the first ＂reality show,＂ An American Family （1973） --has resulted in renewed interest in the series and tangentially its other distinction--its portrayal of the first openly gay character on prime time television. Lance, the oldest of the Loud family children, is on film both flamboyant and effusive, but at the same time-through judicious editing--an asexual creature with no romantic or sexual relationships. This paper considers Lance in the context of Gay representation in media of the 1970s, and then explores the struggle of the filmmakers--and the Loud family themselves--to control and contain the public perception of Lance. The often vague and allusive comments by Lance＇s parents and even Lance himself suggest a character that is at once channing, witty, and vibrantly alive, yet also pretentious and deceitful. The final argument is that these complicit efforts to avoid controversy actually engender it, turning Lance Loud into a figure of mystery and conjecture ... and the undisputed star of the series.展开更多
基金The National Natural Science Foundation of China(No.61301219,61375028,61273266)the Natural Science Foundation of Jiangsu Province(No.BK20130241)+1 种基金the Fundamental Research Funds for the Central Universities(No.2242013K30010)the Science and Technology Program of Nantong(No.BK2014002)
文摘To alleviate the conflict between audibility and distortion in the conventional loudness compensation method, an adaptive multichannel loudness compensation method is proposed for hearing aids. The linear and wide dynamic range compression （WDRC） methods are alternately employed according to the dynamic range of the band-passed signal and the hearing range （HR） of the patient. To further reduce the distortion caused by the WDRC and improve the output signal to noise ratio （SNR） under noise conditions, an adaptive adjustment of the compression ratio is presented. Experimental results demonstrate that the output SNR of the proposed method in babble noise is improved by at least 1.73 dB compared to the WDRC compensation method, and the average speech intelligibility is improved by 6.0% and 5. 7%, respectively, compared to the linear and WDRC compensation methods.
文摘The recent Standard ISO 226 concerning equal-loudness-level contours has been critically analysed. As a result, it is shown that the fitting and smoothing processes applied in the standard lead to parameter values defining equal-loudness-level contours that are not consistent with the chosen loudness function type. Serious mathematical and acoustical discrepancies have also been found that result in constant terms having an unnecessarily high numerical accuracy and a flawed phon definition, which leads to an erroneous loudness level representation. Therefore an extensive treatment of the logarithmic calculations (phon) of a loudness function is performed in this study. Finally, the author concludes that it would be desirable for the discrepancies in the standard (shown in the study) to be taken into account and corrected before publishing a new version of the standard.
文摘A stationary loudness model has been built up on the basis of the former ISO 226: 1987 concerning equal-loudness-level contours. The loudness and loudness level expressions derived in the study include the same parameters as used when determining the equal-loudness-level contours of the former ISO standard. However, as an additional main idea, a loudness summation rule has been proposed in the study. Moreover, the loudness expressions have been normalised to give the same values for people who have a similar sense of hearing. It has also been found that the loudness expressions include basically two different weightings. The first weighting is a conservative frequency weighting in the domain of sound pressure level, and the second weighting consists of coefficients applied to the weighted sound pressure levels. The latter have the greatest effect on the very low-frequency range. Finally, the paper includes a new way to use the A-weighting which takes into account the compressed character of the equal-loudness-level contours at the low frequency range. This method remarkably transforms the character of the A-weighting as a measure for low-frequency environmental noise.
文摘A relation of loudness to loudness just noticeable difference (JND) is derived based on signal detection theory and the hypothesis that loudness is the nerve spike count in the duration of T, and the spike rate distribution of stable tonal stimulus is a stable normal stochastic process. The relation suggests that ratio of loudness JND to loudness of tone is independent of intensity, which can explain well experimental results about the relation of intensity JND to intensity of tone, especially those that could not be explained before such as the Weber fraction hump at the moderate level and the near miss to Weber's law.
文摘Loudness, one of the distinguishing characteristics in auditorium acoustics, has received less attention by acoustical consultants than other parameters up to the present. Due to the lack of an appropriate paramcter, neither measurements in auditorium on this subject is practicable, nor prediction could be made during the design process. The frequently applied method is by means of the summation of the direct sound and the reverberant sound as the total sound level over the audience area. In fact, this is only suitable for predicting the sound level from a steady sound source and in the reverberant field, apparently not appropriate in practice either for acoustic design or for on-site measurement. Strength index G (Starkemass in Germany) (dB), proposed by Lehmann, as loudness criteria, might be a proper parameter. But,as the primary results from our investigation and from others as well, showed that the early reflections presented the main contribution to the perccived loudness, it is more reasonable to set a limit to the integrating time of index G, say 50 ms for speech and 80 ms for music, which have been commonly recognized as useful portion in 'definition' and 'clarity', instead of the infinitive integrating time as Lehmann proposed. Therefore, G50 and G80 are highly recommendedto be used as loudness criteria for speech and music in auditorium acoustics respectfully.
基金supported by the National Natural Science Foundation of China (Grant No. 10674104)
文摘Most of the existing loudness models are based on the diotic listening hypothesis,though human beings always hear in dichotic listening conditions.In this situation,the arithmetic mean of loudness at both ears is usually taken as the approximate value of overall perceived loudness,unaffected by the interaural level difference(ILD).The present work investigated the overall perceived loudness for pure tones in dichotic listening conditions through a subjective experiment.Two experimental procedures and systematic errors were investigated to prove the accuracy of the subjective test.The results showed that fluctuation was insignificant in the low frequency range,while apparent fluctuation of overall loudness could be observed at a high frequency.The overall loudness deviated from the arithmetic mean value as the ILD became larger.A revised model for overall loudness in dichotic listening conditions was proposed.The proposed model and experiment are consistent.
文摘Laughter is a universal language that brings people together.Among all forms of laughter,a loud laugh is particularly powerful.When someone laughs loudly,it can lift the mood of everyone nearby and create a joyful atmosphere.
文摘The strength of a steady sound field in a hall depends on the direct sound levcl and the level of reflections from all boundaries. But for speech and music having impulsive characteristics, only the direct sound and the early reflections are effectivc to the perceived loudness to the listener according to the integrating abili ty of the ear. Therefore, a series of subjective comparison tests are carried out in an anechoic room, using recorded 'dry' speech as testing material are thus con ducted to investigate the contribution of short delayed echoes (early reflections) to thc loudness evaluation. Sound field consisting of primary sound and delayed echoes, single or multiple, are produced by electroacoustic means. Results show that the perceived louopess of the sound field is the function of the echo energy,angle of echo incidence and its temporal distribution. The law of the addition of energy to the echoes with a short delay is not applicable to multiple echoes as well as to a single echo after an interval exceeding 30-50 ms. In certain cases, they are much less than to be expected according to the said law.
文摘The starting point of this study is the theory of tonal consonance by Plomp and Levelt. The major reference point is the theory of Critical Band and its use for evaluating consonance of simple tones. On the basis of such empirical criterion, our aim consists in providing a method of estimating the value of consonance of complex tones, by taking account not only of the number of harmonics, but also of the intensity of the partials which contribute to forming the tone. By introducing a specific algorithm, the level of consonance of a chord of complex tones is expressed in terms both of frequency differences and sound intensity of the partials. The results give rise to a series of considerations and applications, ranging from displaying the order of consonance of all intervals within the octave up to evaluating the hierarchy of chords in the frame of a musical scale.
文摘This study examines the effect of speech level on intelligibility in different reverberation conditions, and explores the potential of loudness-based reverberation parameters proposed by Lee et al. [J. Acoust. Soc. Am., 131(2), 1194-1205 (2012)] to explain the effect of speech level on intelligibility in various reverberation conditions. Listening experiments were performed with three speech levels (LAeq of 55 dB, 65 dB and 75 dB) and three reverberation conditions (T20 of 1.0 s, 1.9 s and 4.0 s), and subjects listened to speech stimuli through headphones. Collected subjective data were compared with two conventional speech intelligibility parameters (Speech Intelligibility Index and Speech Transmission Index) and two loudness-based reverberation parameters (EDTN and TN). Results reveal that the effect of speech level on intelligibility changes with a room’s reverberation conditions, and that increased level results in reduced intelligibility in highly reverberant conditions. EDTN and TN explain this finding better than do STI and SII, because they consider many psychoacoustic phenomena important for the modeling of the effect of speech level varying with reverberation.
文摘On the basis of psychological acoustic theories and experiments, this paper proposes an acoustic model which is based on acoustic perceptual feature. Compared with the physiological acoustics based acoustic model, this model is more suitable to represent human’s perceptual features of continuous speech, so it is suitable for recognition of continuous speech.
文摘A number of studies have been conducted on the improvement of the sound quality of electrical artificial laryngeal speech,the speech produced has been difficult to hear compared to a natural voice.For this reason,it is necessary to effectively improve the frequency characteristics of the input signal.In the present study,to improve the sound quality of vocalization using an electrical artificial larynx,first,a comparison of the frequency characteristics between the real and artificial voices was conducted,and three filters that can make the frequency characteristics of the artificial voice closer to those of a real voice were generated.Then,the influence of these filters on the quality of the artificial voice was investigated via physical measurement and a subjective evaluation experiment targeted at Japanese five vowels.It was found that the intelligibility of artificial/a/and/o/sounds was improved,whereas little improvement was observed in the case of/i/,/u/,and/e/.The obtained results confirmed the effect of optimizing the input signal into the vibration speaker and indicated areas for further improvement.
基金supported by the National Natural Science Foundation of China(11674105)State Key Lab.of Subtropical Building Science,South China University of Technology.
文摘Ambisonics is a series of flexible spatial sound reproduction systems based on spatial harmonics decomposition of sound field.Traditional horizontal and spatial Ambisonics reconstruct horizontal and spatial sound field with certain order of spatial harmonics,respectively.Both the Shannon-Nyquist spatial sampling frequency limit for accurately reconstructing sound field and the complexity of system increase with the increasing order of Ambisonics.Based on the fact that the horizontal localization resolution of human hearing is higher than vertical resolution,mixed-order Ambisonics(MOA)reconstructs horizontal sound field with higher order spatial harmonics,while reconstructs vertical sound field with lower order spatial harmonics,and thereby reaches a compromise between the perceptual performance and the complexity of system.For a given order horizontal Ambisoncis or MOA reproduction,the number of horizontal loudspeakers is flexible,providing that it exceeds some low limit.By using Moore’s revised loudness model,the present work analyzes the influence of the number of horizontal loudspeakers on timbre both in horizontal Ambisonics and MOA reproduction.The binaural loudness level spectra(BLLS)of Ambisoncis reproduction are calculated and then compared with those of target sound field.The results indicate that below the Shannon-Nyquist limit of spatial sampling,increasing the number of horizontal loudspeakers influence little on BLLS then timbre.Above the limit,however,the BLLS for Ambisoncis reproduction deviate from those of target sound field.The extent of deviation depends on both the direction of target sound field and the number of loudspeakers.Increasing the number of horizontal loudspeakers may increase the change of BLLS then timbre in some cases,but reduce the change in some other cases.For MOA,the influence of the number of horizontal loudspeakers on BLLS and timbre reduces when virtual source departs from horizontal plane to the high or low elevation.The subjective evaluation experiment also validates the analysis.
文摘This paper makes comments on conflicts in a micro-story of 527 words,The Ray,written by American writer Ron Milner.The story,from a unique perspective of narration,attracts and strikes the reader as a loud protest amidst silence,against human beings' self-destructive abuse of nuclear technology and craziness of arms races during the cold war.The paper,from the historical,cultural,and religious contexts,presents an analysis of the hero's death and of the message the reader can draw from the story.
文摘The aim of this study is to investigate the biological effects of ion beams on pollen. Pollen grains of Cedrus deodara were implanted with 30 keV nitrogen ion beams at doses ranging from 1 × 10^15 ions/cm^2 to 15 × 10^15 ions/cm^2. The effects of N^＋ implantation on the pollen exine substructure were examined using an atomic force microscope （AFM）, and the structure and morphology of pollen and pollen tubes were observed using a laser scanning confocal microscope （LSCM）. AFM observations distinctly revealed the erosion of the pollen exine caused by N^＋ implantation in the micrometer to nanometer range. Typical results showed that the erosion degree was linearly proportional to the ion dose. Pollen germination experiments in vitro indicated that N^＋ implantation within a certain dose range increased the rate of pollen germination. The main abnormal phenomena in pollen tubes were also analyzed. Our results suggest that low energy ion implantation with suitable energy and dosage can be used to break the pollen wall to induce a transfer of exogenous DNA into the pollen without any damage to the cytoplasm and nuclei of the pollen. The present study suggests that a combination of the method of ion-beam-induced gene transfer and the pollen-tube pathway method （PTPW） would be a new plant transformation method.
文摘Humor is needed universally. The ability to make jokes or to appreciate humor is both necessary for living a happy or smooth life. Different nations have different humors. The paper is to analyze the definition of humor, the difference between British and American humor, and take James Thurber＇s stories to show the typical American humor. The English appear to be deeply serious people. English humor is more conserved, subtle, and silent. The British are known for their sense of humor. However, it is often difficult for foreigners to understand their jokes. The key to understanding British humor is to know that the British often use ＂understatement＂. American humor tends to be more ＂obvious＂ and less oblique, and can sometimes be considered by other English speaking cultures to be over the top and ridiculous.
文摘The continued popularity of reality television, and the release of the recent HBO film Cinema Verite--about the production of the first ＂reality show,＂ An American Family （1973） --has resulted in renewed interest in the series and tangentially its other distinction--its portrayal of the first openly gay character on prime time television. Lance, the oldest of the Loud family children, is on film both flamboyant and effusive, but at the same time-through judicious editing--an asexual creature with no romantic or sexual relationships. This paper considers Lance in the context of Gay representation in media of the 1970s, and then explores the struggle of the filmmakers--and the Loud family themselves--to control and contain the public perception of Lance. The often vague and allusive comments by Lance＇s parents and even Lance himself suggest a character that is at once channing, witty, and vibrantly alive, yet also pretentious and deceitful. The final argument is that these complicit efforts to avoid controversy actually engender it, turning Lance Loud into a figure of mystery and conjecture ... and the undisputed star of the series.
