In This Section
Journal of the AES
2012 May - Volume 60 Number 5
As a spatial-sound processing technique, directional audio coding can determine the direction of arrival of a sound wave. When based on a square array of four omnidirectional microphones, reliable estimation of direction is limited to a restricted frequency range. However, when a rigid cylinder is inserted into the array, the resulting acoustic shadows and scattering allow intermicrophone differences to be used in the quantization. Both methods estimate the direction reliably over the entire audible frequency range. Subjective listening tests corroborate the objective computations.
In small rooms, low-frequency modes have a degrading influence on the quality of the bass components of music. Using objective measures to correct these modes often fails because they do not correspond to the subjective experience of listeners. This research begins with a procedure that elicits a compact set of four verbal descriptors from subjects: articulation, resonance, strength, and depth. These are then mapped to three objective parameters: modal decay time, room volume, and source/receiver position. Results show the importance of reducing the decay time, which then provides an increase in articulation. Discussions suggest ways of extending the results.
Methods to control the unwanted effects of low-frequency modes in critical listening rooms range from complex signal processing to the positioning of loudspeakers and listeners. A rigorous scientific experiment has been conducted to evaluate the perceived quality of eight low-frequency reproduction systems used to control the unwanted effects of room modes in a standard listening room. A strong correlation has been demonstrated between perceived improvements in quality and the decay times of low-frequency energy. For critical listening conditions, those systems ensuring a faster decay of low-frequency energy are preferred over those attempting to “flatten” the magnitude frequency response.
Because dissonance is an important part of music analysis and psychoacoustic research, improving the model for predicting dissonance is useful. In this new model, musical events are assumed to reside in short-term memory, lasting on the range of 3 to 5 seconds. The total dissonance is the sum of the local dissonance from the new event and the interaction with elements in memory. In subjective tests with different kinds of music, the model with memory consistently better predicts listeners’ reports of dissonance. Dissonant sounds in music give rise to a physiological arousal response in listeners.
Standards and Information Documents
AES Standards Committee News
Audio connectors; digital audio measurement; digital audio interfaces; audio file transfer and exchange; audio applications of networks
45th Conference Report, Helsinki
The art of making a living out of music production in the 21st century has changed beyond recognition compared with the situation thirty or forty years ago. AES workshops chaired by Nick Sansano and Jay LeBoeuf shed light on the business practices and technology that are behind the new generation of music production.
49th Conference, London, Call for Papers
50th Conference, Murfreesboro, Call for Papers
Special Issue on Audio Networking, Call for Papers