Martin A. Gold

Case study of soundscape assessment and design methods

A case study of the soundscape assessment and design process for an urban design intervention in a medium‐sized city was conducted as an investigation of acoustical assessment and design methods. A series of long‐term acoustical measurements of average sound levels in the community as well as more detailed measurements and aural recordings of specific acoustic events that comprised the ambient sounds were mapped for the community. Measurements included overall A‐weighted and octave band sound levels and calibrated audio recordings. Sound walks were conducted at various times of day to understand the dynamics of the acoustical environment and to identify issues. Focus group discussions among stakeholders and team members developed the long‐term plans for the community and determined appropriate architectural and acoustical design criteria for the project. The acoustical data were used as the basis for determining design strategies for the urban interventions including reducing, buffering, and mitigating un...

Classroom acoustics III: Acoustical model studies of elementary school classrooms

A 1:4 scale model was constructed with a series of interchangeable wall and ceiling panels to allow a battery of acoustical tests to be conducted for a variety of classroom designs. The walls and ceiling of the room could be changed from sound absorbent to sound reflective materials quickly. Scale furniture was also constructed for the room. The walls of the model could be adjusted from approximately 7 to 10 meters in length and from 2.5 m in height to 7 m in height. Acoustical measurements of speech transmission index, reverberation time, early reverberation time, early‐to‐late energy ratios, loudness (or relative strength), and articulation index were made in a number of simulated elementary school classrooms using both a TEF analyzer and impulse spark techniques. Classrooms where field measurements were taken as described in Classroom Acoustics II were modified to attempt to improve acoustical conditions in the rooms. The location and amount of absorbent material, the location and amount of sound refle...

Background noise levels in classrooms

Field measurements of background noise levels produced by air‐conditioning systems were taken in a sample of 47 elementary school classrooms. Noise levels were grouped by air‐conditioning system type and resulting noise criterion (NC) levels. Eight computer models of classrooms were constructed with varying combinations of absorbent materials on the surfaces of the rooms. A sound source was configured to approximate the normal speaking voice of a teacher in the room. RASTI measures were estimated for six seating locations in each room for background noise levels from 0 dB to NC‐ 55 in 5‐NC point increments. RASTI values remained above 0.8 in seven of the eight rooms at NC levels of 32 and below. RASTI levels decreased to 0.50 and less in all eight rooms at levels of NC‐ 45. The one exception to this was the room constructed with a gypsum board ceiling, vinyl tile floor, and gypsum board walls. Even with no background noise, RASTI values in this room never exceeded 0.60. Background noise levels of NC 32 or...

Classroom acoustics I: The acoustical learning environment: Participatory action research in classrooms

This pilot study used participatory fieldwork in a number of kindergarten through eighth grade classrooms to evaluate the acoustic setting that supports learning. Dynamic interactions among administrators, teachers, students, parents, and research team members makes a difference in learning. It was found that classroom interaction depends on the social make‐up, anticipated behavior, intellectual level, teaching method and theories, and hearing capacity of participants, as well as the physical characteristics of the classrooms. Participatory action research (PAR) resulted in the development of appropriate classroom observation tools utilizing checklists, summary scales, and hierarchial rating scales. The learning climate, lesson clarity, instructional variety, task orientation, and student engagement were used to identify variables for acoustical studies. The PAR was instrumental in determining the protocol for the acoustical measurement studies described in Classroom Acoustics II. Field observations began...

Classroom acoustics II: Acoustical conditions in elementary school classrooms

Acoustical measurements of speech transmission index, reverberation time, early reverberation time, early‐to‐late energy ratios, loudness (or relative strength), articulation index, background noise levels, and signal‐to‐noise ratios were made in a number of elementary school classrooms in one school district to see how many rooms actually had acceptable acoustical conditions. The source and receiver locations for the acoustical measurements were determined through the participatory action research (PAR) described in Classroom Acoustics I. Measurements were made using a TEF analyzer with custom software to compute additional acoustical measurements. Both omni‐directional and directional loudspeakers were used for the source signals. The acoustical measurements were conducted in a variety of source receiver conditions as observed in the PAR studies in the classrooms. General observations are related regarding the relationship between the measurements and the PAR. For example, the STI was always greater tha...

Pilot studies of speech communication in elementary school classrooms

Numerous investigations [Crandell, Smaldino, and Flexer (1995); Nabelek and Nabelek (1994); Olsen (1998)] have demonstrated that the acoustical environment in a classroom is an important variable contributing to the academic and psychosocial achievement of children. Additional studies have shown that children do not obtain adultlike abilities to perceive speech in noise or reverberation until approximately 15 years of age [Crandell (1992); Elliott (1979); Neuman and Horchberg (1985)]. Despite these data, there is very little literature concerning appropriate classroom acoustics for young children. Acoustical measures of reverberation time, early reverberation time, early‐to‐late energy ratios, loudness (or relative strength), Alcons, speech transmission index, background noise levels, and signal‐to‐noise ratios were made across a range of elementary school classrooms to document the acoustical conditions. Speech recognition of children in the rooms was assessed by nonsense syllables and monosyllabic words...

Contrapuntal design: The influence of Bertram Y. Kinzey, Jr., on architectural pedagogy at the University of Florida

Bertram Kinzey introduced modes of analysis, conceptualization, and exploration, as a dedicated and productive researcher, author, teacher, architect, consultant, and musician that were transformative and continue to reverberate internationally through the work of his students. Bert’s insightful theoretical and practical relationships between music, acoustics, and architecture were drawn from his reflective approach to teaching and refined through active practice. Perhaps foundational to his educational contribution, is his interest and talent as an organist and organ builder leading to his use of “contrapuntal” to describe the interaction of music and architecture—new notes overlapping those lingering in the space and time of reverberance. Overlapping, independent, yet harmonizing elements might also describe Bert’s approach to architectural design as a theoretical construct; an integrative process; and as a measure of great architecture. Contrapuntal thinking is well known in literature and music but is...

Effects of multiple directional sources on quantitative and qualitative analyses of concert hall acoustics

The “orchestral impulse reponse” measurement technique using multiple directional sources and its effects on quantitative analysis of concert hall acoustics were discussed earlier [Kwon and Siebein, J. Acoust. Soc. Am. 120, 3263(A) (2006)]. An array with 16 directional loudspeakers approximating overall sound radiation patterns of each instrumental group of an orchestra was incorporated for room acoustical measurements and analyses. As a continuous study, this paper discusses qualitative assessments of concert hall acoustics over room subjective parameters including reverberance, clarity, warmth, spaciousness, envelopment, etc. The music signals binaurally recorded in a performance hall with the same source array were evaluated by means of subjective listening tests in comparison to those recorded with the single omni‐directional source (dodec). The results showed that some perceived differences are present between the array with multiple directional sources and the one with a single omni‐directional sour...

Qualitative analysis of concert hall acoustics with multiple directional sources

Following the previous work on quantitative analysis of concert hall acoustics with multiple directional sources (16 directional loudspeakers) [Kwon and Siebein, J. Acoust. Soc. Am. 120, 3263(A) (2006)], this paper discusses qualitative assessments of concert hall acoustics by means of psycho‐acoustical listening tests of room acoustical qualities such as loudness, reverberance, clarity, warmth, spaciousness, envelopment, etc. The music signals binaurally recorded in a performance hall with the same multiple directional source array were evaluated in comparison to those recorded with the single omni‐directional source. Results showed that some of the room acoustical qualities of the music signals recorded with multiple directional sources were perceived noticeably different from those recorded with a single omni‐directional source. In the main orchestra area at 95% significance level, the music recording with multiple directional sources was perceived more in reverberance and clarity but less in warmth. S...

Effects of specular and diffuse reflections on perceived music quality

The purpose of this study was to investigate the effects of temporal distribution of diffuse and specular reflections on the perceived acoustic qualities of music performance. Sets of impulse responses were designed with different temporal distributions of early acoustic energy (specular and diffuse reflections). Then, three types of anechoic sound sources, orchestral music, trumpet, and piano, were convolved with the designed impulse responses. The results from the listening tests revealed that different room environments were needed to acoustically support different source characteristics: (1) A large number of diffuse reflections arriving within 40 and 80 ms of the direct sound improved perceived intimacy, texture, and overall impression for all sound sources; heightened perceived clarity for trumpet and piano; and reduced perceived glare for trumpet. (2) Diffuse reflections arriving between 80 and 160 ms of the direct sound preserved perceived reverberance and reduced perceived echoes as opposed to sp...