It is well established that musical sounds comprising multiple partials with frequencies approximately in the ratio of small integers give rise to a strong sensation of pitch even if the lowest or fundamental partial ...It is well established that musical sounds comprising multiple partials with frequencies approximately in the ratio of small integers give rise to a strong sensation of pitch even if the lowest or fundamental partial is missing—the so-called virtual pitch effect. Experiments on thirty test subjects demonstrate that this virtual pitch is shifted significantly by changes in the spacing of the constituent partials. The experiments measured pitch by comparison of sounds of similar timbre and were automated so that they could be performed remotely across the Internet. Analysis of the test sounds used shows that the pitch shifts are not predicted by Terhardt’s classic model of virtual pitch. The test sounds used were modelled on the sounds of church bells, but a further experiment on seventeen test subjects showed that changes in partial amplitude only had a minor effect on the pitch shifts observed, and that a pitch shift was still observed when two of the lowest frequency partials were removed, so that the effects reported are of general interest.展开更多
文章以达拉皮科拉《献给安娜莉贝拉的音乐札记》(Quaderno Musicale di Annalibera)为例,通过不同的分析视角与方法,对其各乐章的不同音高组织结构即12音序列内部结构及序列之间的发展逻辑的特点进行凸现与分类,试图阐明12音序列作品中...文章以达拉皮科拉《献给安娜莉贝拉的音乐札记》(Quaderno Musicale di Annalibera)为例,通过不同的分析视角与方法,对其各乐章的不同音高组织结构即12音序列内部结构及序列之间的发展逻辑的特点进行凸现与分类,试图阐明12音序列作品中除以序列内部顺序作为结构特征之外,还通过共有相同音级子集、强调微观音程与宏观路径的对称性等建构音高组织的多重结构思路。展开更多
A distributed feedback(DFB) semiconductor laser with three phase shifts based on reconstruction equivalent chirp(REC) technology is proposed and investigated numerically.With the combination of multiple phase shifts a...A distributed feedback(DFB) semiconductor laser with three phase shifts based on reconstruction equivalent chirp(REC) technology is proposed and investigated numerically.With the combination of multiple phase shifts and corrugation pitch modulated(CPM) structure,we also propose a novel and more complex structure named dual CPM,which has a flatter light power distribution along the laser cavity compared with the true double phase shifts DFB laser diode(LD),while the P-I curves are nearly the same.The proposed dual CPM structure is also designed and analyzed based on REC technology.The simulation results show that,the DFB semiconductor laser with complex structure such as phase shifts,or even arbitrary variation of the grating period can be achieved equivalently and easily by changing the sampling structure.But its external characteristics are almost the same as those DFB lasers with true phase shifts,or true arbitrary variation of the grating period.The key advantage of the REC technology is that it varies only the sampling structure and keeps the seed grating(actual grating in sampling structure) period constant.So its fabrication needs only low-cost and standard holographic exposure technology.Therefore we believe this method can achieve the high-end and low-cost DFB LD for mass production.展开更多
We are looking for a mathematical model of monophonic sounds with independent time and phase dimensions. With such a model we can resynthesise a sound with arbitrarily modulated frequency and progress of the timbre. W...We are looking for a mathematical model of monophonic sounds with independent time and phase dimensions. With such a model we can resynthesise a sound with arbitrarily modulated frequency and progress of the timbre. We propose such a model and show that it exactly fulfils some natural properties, like a kind of timeinvariance, robustness against non-harmonic frequencies, envelope preservation, and inclusion of plain resampling as a special case. The resulting algorithm is efficient and allows to process data in a streaming manner with phase and shape modulation at sample rate, what we demonstrate with an implementation in the functional language Haskell. It allows a wide range of applications, namely pitch shifting and time scaling, creative FM synthesis effects, compression of monophonic sounds, generating loops for sampled sounds, synthesise sounds similar to wavetable synthesis, or making ultrasound audible.展开更多
文摘It is well established that musical sounds comprising multiple partials with frequencies approximately in the ratio of small integers give rise to a strong sensation of pitch even if the lowest or fundamental partial is missing—the so-called virtual pitch effect. Experiments on thirty test subjects demonstrate that this virtual pitch is shifted significantly by changes in the spacing of the constituent partials. The experiments measured pitch by comparison of sounds of similar timbre and were automated so that they could be performed remotely across the Internet. Analysis of the test sounds used shows that the pitch shifts are not predicted by Terhardt’s classic model of virtual pitch. The test sounds used were modelled on the sounds of church bells, but a further experiment on seventeen test subjects showed that changes in partial amplitude only had a minor effect on the pitch shifts observed, and that a pitch shift was still observed when two of the lowest frequency partials were removed, so that the effects reported are of general interest.
文摘文章以达拉皮科拉《献给安娜莉贝拉的音乐札记》(Quaderno Musicale di Annalibera)为例,通过不同的分析视角与方法,对其各乐章的不同音高组织结构即12音序列内部结构及序列之间的发展逻辑的特点进行凸现与分类,试图阐明12音序列作品中除以序列内部顺序作为结构特征之外,还通过共有相同音级子集、强调微观音程与宏观路径的对称性等建构音高组织的多重结构思路。
基金supported by the National Natural Science Foundation of China (60877043)the National High-Tech Research & Development Program of China (2007AA03Z417)the New-Century Excellent Talents Supporting Program of the Ministry of Education of China
文摘A distributed feedback(DFB) semiconductor laser with three phase shifts based on reconstruction equivalent chirp(REC) technology is proposed and investigated numerically.With the combination of multiple phase shifts and corrugation pitch modulated(CPM) structure,we also propose a novel and more complex structure named dual CPM,which has a flatter light power distribution along the laser cavity compared with the true double phase shifts DFB laser diode(LD),while the P-I curves are nearly the same.The proposed dual CPM structure is also designed and analyzed based on REC technology.The simulation results show that,the DFB semiconductor laser with complex structure such as phase shifts,or even arbitrary variation of the grating period can be achieved equivalently and easily by changing the sampling structure.But its external characteristics are almost the same as those DFB lasers with true phase shifts,or true arbitrary variation of the grating period.The key advantage of the REC technology is that it varies only the sampling structure and keeps the seed grating(actual grating in sampling structure) period constant.So its fabrication needs only low-cost and standard holographic exposure technology.Therefore we believe this method can achieve the high-end and low-cost DFB LD for mass production.
文摘We are looking for a mathematical model of monophonic sounds with independent time and phase dimensions. With such a model we can resynthesise a sound with arbitrarily modulated frequency and progress of the timbre. We propose such a model and show that it exactly fulfils some natural properties, like a kind of timeinvariance, robustness against non-harmonic frequencies, envelope preservation, and inclusion of plain resampling as a special case. The resulting algorithm is efficient and allows to process data in a streaming manner with phase and shape modulation at sample rate, what we demonstrate with an implementation in the functional language Haskell. It allows a wide range of applications, namely pitch shifting and time scaling, creative FM synthesis effects, compression of monophonic sounds, generating loops for sampled sounds, synthesise sounds similar to wavetable synthesis, or making ultrasound audible.
