The effect of direct-to-reverberant ratio (dRR) on front-back confusion in binaural reproduction was investigated. Binaural room impulse responses (BRiRs) of loudspeakers at 0 degrees and 180 degrees azimuths from the...
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ISBN:
(纸本)9781665409988
The effect of direct-to-reverberant ratio (dRR) on front-back confusion in binaural reproduction was investigated. Binaural room impulse responses (BRiRs) of loudspeakers at 0 degrees and 180 degrees azimuths from the listening position were capturedin an iTU-R BS.1116-3-compliant listening room (RT=0.25s) using a KU100 dummy head placed 2m away from each loudspeaker. The dRRs of the original BRiRs were manipulated by varying the levels of the reverberant parts (beyond 2.5ms after the direct sound) of the signals, producing BRiRs with dRRs ranging from -12 dB to 12 dB with 4 dB intervals for each source position, as well as a pseudo-anechoic HRiR condition. Five subjects participatedin the initial listening test. Each front or back stimulus with a different dRR was presented 20 times in a random order and the subject's task was to respond either Front or Back. from psychometric functions derivedfrom the data collected, a consistent pattern was observedfrom all subjects in that a lower dRR (more reverberant) tended to cause a higher rate of front-to-back confusion, whereas a higher dRR produced a higher rate of back-to-front confusion. The dRR thresholds of discrimination were different between the front and rear located sources, and the region between the two thresholds is proposed as a transition region where an extreme chance of confusion can be avoided for both source positions.
Underground stations are a common communication situation in towns: we talk with friends or colleagues, listen to announcements or shop for titbits while background noise and reverberation are challenging communicatio...
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ISBN:
(纸本)9781665409988
Underground stations are a common communication situation in towns: we talk with friends or colleagues, listen to announcements or shop for titbits while background noise and reverberation are challenging communication. Here, we perform an acoustical analysis of two communication scenes in an underground station in Munich and assess speech intelligibility. The acoustical conditions were measuredin the station and room acoustics simulations in the real-time Simulated Open Field Environment (rtSOFE) are performed: We compare binaural room impulse responses measured with an artificial headin the station to modeledimpulse responses for free-field auralization via 60 loudspeakers in the rtSOFE. We used the image source method to model early reflections and a set of multi-microphone recordings to model late reverberation. The first communication scene consists of 12 equidistant (1.6 m) horizontally spaced source positions around a listener, simulating different direction-dependent conditions. The second scene mimics an approaching speaker across six radially spaced source positions (from 1 m to 10 m) with varying direct sound level and thus direct-to-reverberant energy. The acoustic parameters of the underground station show a moderate amount of reverberation (T30 in octave bands was between 2.3 s and 0.6 s and early-decay times between 1.46 s and 0.46 s). The binaural and energetic parameters of the auralization were in a close match to the measurement. Measured speech reception thresholds were within the error of the speech test, indicating that the auralized simulation reproduces acoustic and perceptually relevant parameters for speech intelligibility with high accuracy.
The reproduction of diffuse soundis one of the important issues in multichannel audio. in the room acoustics, the interaural cross-correlation coefficient (iACC) is known as an objective measure of diffuseness. it us...
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ISBN:
(纸本)9781665409988
The reproduction of diffuse soundis one of the important issues in multichannel audio. in the room acoustics, the interaural cross-correlation coefficient (iACC) is known as an objective measure of diffuseness. it uses a binaural signal recorded by a dummy-head microphone set in the sound field. in the audio reproduction, however, the iACC is not a good measure because the diffuse sound comes only from the loudspeakers' directions instead of every direction. Although the inter-channel cross-correlation coefficient (iCC) among channel signals has been used to estimate the diffuseness of audio reproduction, the actual diffuseness in the reproduction should be dependent on loudspeaker positions of the reproduction system. This study addresses a new method for objective evaluation of diffuseness in audio reproduction based on the binaural signal. The method analyzes the influence of loudspeakers on the interaural cross-correlation function (iACF) and uses a weighting function for iACF to reduce the influence. The weightediACC that is obtainedfrom the weightediACF is then proposed as a new measure of diffuseness for audio reproduction. Subjective evaluation experiment was conducted using binaural sound materials recorded by a dummy-head microphone set in the sound field of audio reproduction. Eleven people evaluated these binaural signals by a headphone reproduction paying attention to the diffuseness and timbre of sound. The subjective evaluation results were compared with the calculated values by the new method. As the result, it is found that the values accorded with the subjective evaluation results, meaning that the new method can generate an appropriate objective measure of diffuseness for audio reproduction.
The reproduction of diffuse soundis one of the important issues in multichannel audio. in the room acoustics, the interaural cross-correlation coefficient (iACC) is known as an objective measure of diffuseness. it us...
The reproduction of diffuse soundis one of the important issues in multichannel audio. in the room acoustics, the interaural cross-correlation coefficient (iACC) is known as an objective measure of diffuseness. it uses a binaural signal recorded by a dummy-head microphone set in the sound field. in the audio reproduction, however, the iACC is not a good measure because the diffuse sound comes only from the loudspeakers’ directions instead of every direction. Although the inter-channel cross-correlation coefficient (iCC) among channel signals has been used to estimate the diffuseness of audio reproduction, the actual diffuseness in the reproduction should be dependent on loudspeaker positions of the reproduction system. This study addresses a new method for objective evaluation of diffuseness in audio reproduction based on the binaural signal. The method analyzes the influence of loudspeakers on the interaural cross-correlation function (iACF) and uses a weighting function for iACF to reduce the influence. The weightediACC that is obtainedfrom the weightediACF is then proposed as a new measure of diffuseness for audio reproduction. Subjective evaluation experiment was conducted using binaural sound materials recorded by a dummy-head microphone set in the sound field of audio reproduction. Eleven people evaluated these binaural signals by a headphone reproduction paying attention to the diffuseness and timbre of sound. The subjective evaluation results were compared with the calculated values by the new method. As the result, it is found that the values accorded with the subjective evaluation results, meaning that the new method can generate an appropriate objective measure of diffuseness for audio reproduction.
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