Subjective evaluation of acoustics was studied by recording nine concert halls with a simulated symphony orchestra on a seat 12 m from the orchestra. The recorded music was spatially reproduced for subjective listening tests and individual vocabulary profiling. In addition, the preferences of the assessors and objective parameters were gathered. The results show that concert halls were discriminated using perceptual characteristics, such as Envelopment/Loudness, Reverberance, Bassiness, Proximity, Definition, and Clarity. With these perceptual dimensions the preference ratings can be explained. Seventeen assessors were divided into two groups based on their preferences. The first group preferred concert halls with relatively intimate sound, in which it is quite easy to hear individual instruments and melody lines. In contrast, the second group preferred a louder and more reverberant sound with good envelopment and strong bass. Even though all halls were recorded exactly at the same distance, the preference is best explained with subjective Proximity and with Bassiness, Envelopment, and Loudness to some extent. Neither the preferences nor the subjective ratings could be fully explained by objective parameters (ISO3382-1:2009), although some correlations were found.
1 January 2010 in Acta Acustica united with Acustica
The sound radiation patterns of musical instruments represent a considerable part of the perceived room acoustics. The directivities of fourteen common symphony orchestra instruments and a soprano singer during performance are investigated. For this purpose, each instrument was recorded with the musician in an anechoic room with 22 microphones distributed around the player. As the result, directivities of the strings and woodwind instruments are noticed to change with the played tone while the brass instruments radiate constantly in the direction of the bell. Playing dynamics was not found to affect the directivity although the spectrum of the sound changes considerably in particular with the brass instruments. The results can be utilized with source modeling in room acoustics simulation and in research on musical acoustics.
30 January 2013 in The Journal of the Acoustical Society of America
Acousticians and other practitioners alike often describe acoustic conditions in performance spaces with standard objective parameters. Apart from a few exceptions, the parameters are calculated by integrating the sound energy of the impulse responses over time; this makes them inadequate for researching the acoustics in detail, especially in the early part of the room impulse response. This paper proposes a method based on time-frequency and spatiotemporal presentations to overcome the lack of detail in the standard analysis. In brief, the proposed methods visualize the cumulative development of the sound field as a function of frequency or direction by forward-integrating the energy in the impulse response in short time frames. Analysis on the measurements from six concert halls concentrates particularly on interpreting the results in light of the seat dip effect. Earlier research has concluded that the seat dip effect is reduced by reflection from low overhead surfaces. In contrast, the current results indicate that the seat dip attenuation in the frequency response is corrected the best when the hall provides most lateral reflections. These findings suggest that the proposed analysis is suitable for explaining concert hall acoustics in detail.
13 January 2011 in The Journal of the Acoustical Society of America
Measurements of impulses produced by bursting balloons are presented. Various sizes of balloons were popped with a mechanical device in an anechoic chamber and recorded with a spherical microphone array. The power responses and directivity of the balloons are analyzed. Results indicate that power responses have two emphasized frequencies which depend on balloon size and inflation level. Larger balloons radiated more energy and higher inflation levels resulted in stronger high frequency content. Balloon directivity patterns are stable over repetitions. However, balloons do not radiate omnidirectionally. The degree of omnidirectionality improves with balloon size and for midrange frequencies.
1 June 2011 in The Journal of the Acoustical Society of America
Strong, exciting, and engaging sound is perceived in the best concert halls. Here, it is shown that wideband early reflections that preserve the temporal envelope of sound contribute to the clear and open acoustics with strong bass. Such reflections are fused with the direct sound due to the precedence effect. In contrast, reflections that distort the temporal envelope render the sound weak and muddy because they partially break down the precedence. The presented findings are based on the earlier psychoacoustics research, and confirmed by a perceptual evaluation with six simulated concert halls that have same monaural room acoustical parameter values according to ISO3382-1.