AES New York 2015
Engineering Brief EB7
EB7 - Posters 2
Sunday, November 1, 12:00 pm — 1:30 pm (S-Foyer 1)
EB7-1 Measuring Speech Intelligibility Loss in Single-Driver Panel Loudspeakers—David Anderson, University of Rochester - Rochester, NY, USA; Mark F. Bocko, University of Rochester - Rochester, NY, USA
The impulse response of a panel loudspeaker with a single moving-coil driver contains ringing due to the resonant frequencies, but the implication of this type of response for intelligible reproduction of speech signals is the subject of some debate. The impulse responses of three examples of such loudspeakers of various sizes and materials were measured in an anechoic environment and compared to that of a conventional speaker. Reverberation effects are clear and calculation of the Speech Transmission Index (STI) confirms a loss of intelligibility; the STI values of the plate loudspeakers are 6% to 13% lower than that of the conventional speaker. Spectrograms of reproduced speech by each plate also show a considerable loss of detail.
Engineering Brief 228 (Download now)
EB7-2 Vibrational Analysis of Vintage Planar Loudspeakers—Michael Heilemann, University of Rochester - Rochester, NY, USA; David Anderson, University of Rochester - Rochester, NY, USA; Mark F. Bocko, University of Rochester - Rochester, NY, USA
Recently, there has been a strong interest in the development of flat-panel loudspeakers. The Yamaha JA4001 and the Poly-planar P20 represent two early attempts at commercializing the technology. The responses of both loudspeakers were analyzed using a laser vibrometer. The scans for each panel depict sharp peaks in the frequency response, which correspond to resonant modes. The presence of additional modes is similar to the effect of cone breakup in traditional loudspeakers. Impulse response measurements show that low-frequency modes are highly reverberant. Studying these early planar loudspeakers can provide valuable insight for the further development of such technology.
Engineering Brief 229 (Download now)
EB7-3 A Database of Loudspeaker Polar Radiation Measurements—Joseph G. Tylka, 3D3A Lab, Princeton University - Princeton, NJ, USA; Rahulram Sridhar, 3D3A Lab, Princeton University - Princeton, NJ, USA; Edgar Choueiri, Princeton University - Princeton, NJ, USA
Anechoic directivity data for a variety of loudspeakers have been measured and compiled into a freely available online database, which may be used to evaluate these loudspeakers based on their directivities. The measurements are illustrated through four types of plots (frequency response, polar, contour, and waterfall) and are also given as raw impulse responses. Two sets of directivity metrics are defined and are used to rank the loudspeakers. The first set consists of full and partial directivity indices that isolate sections of the loudspeaker’s radiation pattern (e.g., forward radiation alone) and quantify its directivity over those sections. The second set quantifies the extent to which the loudspeaker exhibits constant directivity. Measurements are taken, in an anechoic chamber, along horizontal and vertical orbits with a (nominal) radius of 1.6 m and an angular resolution of five degrees.
Engineering Brief 230 (Download now)
EB7-4 Single-Channel Sound Source Separation Using NMF with Sparseness Constraints—Shijia Geng, University Of Miami - Miami, FL, USA; Colby N. Leider, University of Miami - Coral Gables, FL, USA
While challenging, sound source separation is a task that has many practical applications in audio signal processing. In this paper three sound files with two sources in each were separated using the non-negative matrix factorization (NMF) approach, with and without sparseness constraints. The results showed that adding sparseness constraints had no effect when separating drums and bass guitar but had better performances when separating piano and drums, and piano and bass guitar.
Engineering Brief 231 (Download now)
EB7-5 Noise Robust End-Point Detection Algorithm Using Human Auditory and Pronunciation Characteristics—Jae-hoon Jeong, Samsung Electronics Co. Ltd. - Suwon, Korea; Min Seok Kwon; Seungyeol Lee, Samsung Electronics Co. Ltd. - Suwon-si, Gyeonggi-do, Korea; Young Woo Lee; Haruyuki Mori; Namgook Cho; Jae Won Lee, DMC R&D Center, Samsung Electronics Co. - Suwon, Gyeonggi-do, Korea
A noise robust end point detection algorithm is proposed that could be used in real environment speech recognition. Inaccurate end point detection brings not only speech recognition performance reduction but also users’ tiredness. EPD algorithms based on energy level change or speech presence probability are vulnerable to high energy noises. After reducing much noise by auditory filter, one of human speech pronunciation characteristic, syllabic rate is used for checking if there is still speech component or not. The proposed algorithm shows much better performance in real environments like TV sound noise, café noise, etc.
Engineering Brief 233 (Download now)
EB7-6 Evaluation of Separation Techniques for Musical Instrument Recordings Using Microphone Array in a Rehearsal Room—Tomasz Zernicki, Zylia sp. z o.o. - Poznan, Poland; Lukasz Januszkiewicz, Zylia Sp. z o.o. - Poznan, Poland; Marcin Chryszczanowicz, Zylia sp. z.o.o. - Poznan, Poland; Piotr Makaruk, Zylia - Poznan, Poland; Jakub Zamojski, Zylia sp. z.o.o. - Poznan, Poland
This paper describes the comparison of two different approaches for fast and simple sound tracks separation of multiple musical instrument records. An uniform circular microphone array is used in a rehearsal room for recording of musical instruments being played simultaneously. A beamforming algorithm and additional signal post-processing is used to separate the individual instrument tracks. The separated tracks are compared to tracks recorded with dedicated highly directive microphone (shotgun). The objective evaluation of results is made by calculation of signal-to-interference ratio (SIR). Additionally the subjective test are performed where listeners had to asses the quality in terms of level of interference signals.
Engineering Brief 234 (Download now)
EB7-7 Monitoring and Authoring of 3D Immersive Next Generation Audio Formats—Peter Pörs, Junger Audio GmbH - Berlin, Germany
The next generation immersive audio formats will require changes in the audio production workflow. Monitoring the audio along with authoring and verifying of dynamic metadata will become a new challenge. New procedures for managing object based encoded content the same way as for personalization of services through the selection of alternative audio objects (such as commentator languages) needs to be established. Loudness control during production and the loudness definition for the final output formats are other topics to consider. A Monitoring & Authoring Unit must be compatible with upcoming immersive multichannel 3D audio formats and should offer a platform to host all the emerging immersive 3D audio encoding formats from different vendors.
Engineering Brief 235 (Download now)
