Preschool room acoustics - collected and analysed data in the research project SPACE (Supportive Preschool AcoustiC Environment)

The data set contains the results of room acoustic measurements and additional information from 57 rooms in 19 different public preschools in the Gothenburg area (Sweden). The measurements were conducted during 2019-2020. Children at preschool are divided into units commonly, but not always, based on age. The presented data covers in total 31 different units aimed at older children. Up to three rooms per unit were measured, focusing on the main play rooms and the meal room. In cases where these rooms were the same, only one room per unit was measured. The preschools are divided into three groups, strata, based on the year when they were built: 1980-1994, 1995-2006, and 2007-2018. To reach an even distribution within each strata with respect to socioeconomic factors, we used an existing preschool-specific index acquired from the central preschool administration [Jorsäter, M., Resursfördelningsmodell Göteborg 2019. 2019, Statistics Sweden (SCB)] (attached as a PDF file). The index is based on a model from Statistics Sweden (SCB) where school performance after elementary school is linked with a number of explanatory variables related to the socioeconomic background of the individual child and her/his parents. When these factors are known for the children at a specific preschool, an averaged index is calculated, centered around 100. Preschools with an index over 100 have a larger share of children with a risk of not qualifying for high school (gymnasium). Preschools with an index less than 100 have a smaller share of children with a risk of not qualifying for high school. The purpose of the index is to prioritize economic support to school units with the highest need and increase equity. Room acoustic parameters and unoccupied noise levels were measured in each room using a laptop and an external 8-channel sound card (HEAD acoustics SQuadriga II). An omnidirectional sound source with a built-in generation of pink noise (50-20000 Hz) was used to excite the room. A modification was made to the device in order to extract the electronic signal from the loudspeaker. Unoccupied noise levels were measured in accordance with ISO 16032:2004. In some rooms the contribution from the ventilation could be estimated by conducting the measurements with the ventilation unit turned on and off separately. Room acoustic measurements were conducted following the precision method in ISO 3382-2:2008. Three microphones were used simultaneously with predetermined height intervals (1±0.2, 1.4±0.2, 1.6±0.2). The standard’s recommendation to use natural source positions was implemented by placing the loudspeaker where we estimated that a child would have its head during sitting and standing activities in the room. In addition, a corner position was always used. Impulse responses were calculated by the software ArtemiS SUITE using the loudspeaker's extracted electronic signal as the reference. Impulse responses and unoccupied sound pressure level spectra were exported to Matlab. Octave band room acoustic parameters were calculated for 125 – 8000 Hz from the impulse responses with the ITA-toolbox 8.6 [Berzborn, M., et al., The ITA-Toolbox: An Open Source MATLAB Toolbox for Acoustic Measurements and Signal Processing, in DAGA 2017. 2017: Kiel.]. The analysis was done for reverberation time T20 and EDT (Early decay time), and Speech Clarity, C50. An addition to the code was made to evaluate the Clarity index with a shorter time, C35, which uses 35 ms instead of the default 50 ms as suggested by Whitlock and Dodd [Whitlock, J.A.T. and G. Dodd, Speech Intelligibility in Classrooms: Specific Acoustical Needs for Primary School Children. Building Acoustics, 2008. 15(1): p. 35-47.] Sound strength, G (dB), was calculated from the sound power of the loudspeaker LW (measured according to the ISO 3741 standard) and the resulting sound pressure level Lp in a measurement point: G=Lp - LW + 31 [SS-EN ISO 3382-1:2009]. Additional information collected during the measurements: Dimensions and shape of the room The floor and wall type of construction material is classified into heavy or lightweight A subjective evaluation of the degree of furnishing and categorized as sparse, normal or dense. Material type of the acoustic treatment in the ceiling: porous type (typical white mineral wool) or other various types, e.g. perforated gypsum boards Sound absorption on the walls* and their approximate total area *The concept wall absorption is interpreted as a fabric or porous material mounted on, or in the vicinity of a wall and which was subjectively judged as acoustically absorbing. The data set consists of seven spreadsheet files where each row contains data from one preschool room. Each preschool room is identified with 4 numbers: ROOM_ID1: Represents building year interval: “1”=1980-1994, “2”=1995-2006, “3”=2007-2018 ROOM_ID2: Represents the number of the preschool within each building year interval ROOM_ID3: Represents the unit number within each preschool ROOM_ID4: Represents the room number within each unit Missing data is indicated with an empty cell. The data is also available as semicolon-separated .csv files. --- --- --- XLSX-file “INFO” SES = Socioeconomic index of preschool Volume = Volume of room in (m3) FloorA = Floor area (m2) Height_min / Height_max = height to inner ceiling (m) FurnDeg = Subjective furnishing degree, 1 = spares, 2 = normal, 3 = dense FloorConst = Floor construction, 1 = lighweight, 2 = heavy (concrete) WallConst = Wall construction, 1 = lightweight, 2 = heavy, 3= mixed CeilingAbs = Acoustic ceiling, 1 = porous (mineral wool), 2 = other (commonly perforated boards) wallAbs = Amount of wall absorbers (m2) --- --- --- Measured room acoustic parameters are presented as room-averaged for the three different microphone heights separately: low = 1±0.2, mid = 1.4±0.2 and high = 1.6±0.2 m and for the octave bands from 125 Hz to 8000 Hz: XLSX-file “T20” Reverberation time T20 (s) XLSX-file “EDT” Early decay time (s) XLSX-file “G” Sound strength (dB) XLSX-file “C50” Speech Clarity (dB) XLSX-file “C35” Speech Clarity with integration time 35 ms (dB) --- --- --- Measured unoccupied noise levels are presented as Leq (equivalent) levels in 1/3 octave bands from 25 Hz to 10000 Hz in the spreadsheet file “BKG.xlsx”. For some rooms there is also an estimated contribution from the ventilation system to the background noise equivalent level. XLSX-file “BKG” Equivalent level (dB) --- --- ---本数据集包含瑞典哥德堡地区19所不同公立幼儿园的57个房间的室内声学测量结果及附加信息，测量工作于2019-2020年间开展。幼儿园的儿童通常按年龄划分为不同单元，但并非总是如此。本次公开的数据涵盖了总计31个面向大龄儿童的单元，每个单元最多测量3个房间，重点为主游戏室和用餐室；若二者为同一房间，则每个单元仅测量一间。 本批幼儿园按建造年份划分为三个分层组：1980-1994年、1995-2006年及2007-2018年。 为了在各分层组内实现社会经济因素的均衡分布，我们采用了从中央幼儿园管理部门获取的现有幼儿园专属指数[Jorsäter, M., Resursfördelningsmodell Göteborg 2019. 2019, 瑞典统计局（SCB）]（附PDF文件）。该指数基于瑞典统计局（SCB）的模型，将小学毕业后的学业表现与多个与儿童及其父母社会经济背景相关的解释变量相关联。当某所幼儿园的儿童相关信息已知时，即可计算出以100为中心的平均指数。指数高于100的幼儿园，其儿童中无法升入高中（gymnasium）的比例更高；指数低于100的幼儿园，该比例则更低。该指数的目的在于将经济支持优先分配给最有需求的学前单元，以提升教育公平性。 每个房间的室内声学参数与空置噪声水平均通过笔记本电脑及外置8通道声卡（HEAD acoustics SQuadriga II）进行测量。采用内置粉红噪声（50-20000 Hz）发生功能的全指向声源激励房间，并对该设备进行了改造，以提取扬声器的电子信号作为参考。 空置噪声水平的测量符合ISO 16032:2004标准。部分房间可通过分别开启和关闭通风设备进行测量，以此估算通风系统带来的噪声贡献。 室内声学测量遵循ISO 3382-2:2008标准的精密测量方法，同时使用三台麦克风，按预设高度间距布置（1±0.2 m、1.4±0.2 m及1.6±0.2 m）。标准中推荐采用自然声源位置，我们将扬声器放置在预估的儿童在房间内就坐、站立活动时头部所处的位置，同时始终增设一个角落位置作为声源点。通过ArtemiS SUITE软件，以提取的扬声器电子信号作为参考，计算得到房间冲激响应。 冲激响应与空置声压级频谱均导出至Matlab。使用ITA-toolbox 8.6[Berzborn, M.等, The ITA-Toolbox: An Open Source MATLAB Toolbox for Acoustic Measurements and Signal Processing, in DAGA 2017. 2017: Kiel.]，从冲激响应中计算得到125–8000 Hz倍频程带的室内声学参数。分析对象包括混响时间T20、早期衰变时间（EDT）、语言清晰度C50。此外，我们对代码进行了扩展，以计算积分时长为35 ms的清晰度指数C35，替代Whitlock与Dodd[Whitlock, J.A.T.和G. Dodd, Speech Intelligibility in Classrooms: Specific Acoustical Needs for Primary School Children. Building Acoustics, 2008. 15(1): p. 35-47.]提出的默认50 ms时长。 声强G（dB）通过扬声器的声功率LW（按ISO 3741标准测量）与测量点处的声压级Lp计算得到：G = Lp - LW + 31 [SS-EN ISO 3382-1:2009]。 测量期间收集的附加信息包括： - 房间尺寸与形状 - 地板与墙体的建筑材料类型，分为重型或轻型 - 家具配置程度的主观评价，分为稀疏、常规或密集三类 - 天花板声学处理材料类型：多孔类（典型为白色矿棉）或其他各类类型（如穿孔石膏板） - 墙面吸声材料*及其近似总面积 *墙面吸声的定义为：安装于墙体上或墙体附近、经主观判定具备声学吸声性能的织物或多孔材料。 本数据集包含7个电子表格文件，每行数据对应一所幼儿园的一间房间。每间房间通过4组数字进行标识： ROOM_ID1：代表建造年份区间，“1”=1980-1994年，“2”=1995-2006年，“3”=2007-2018年 ROOM_ID2：代表各建造年份区间内的幼儿园编号 ROOM_ID3：代表该幼儿园内的单元编号 ROOM_ID4：代表该单元内的房间编号 缺失数据以空白单元格表示。 数据同时以分号分隔的.csv文件格式提供。 --- --- --- XLSX文件"INFO" SES = 幼儿园社会经济指数 Volume = 房间体积（单位：m³） FloorA = 地板面积（单位：m²） Height_min / Height_max = 内部天花板高度（单位：m） FurnDeg = 家具配置程度主观评分：1=稀疏，2=常规，3=密集 FloorConst = 地板结构：1=轻型，2=重型（混凝土） WallConst = 墙体结构：1=轻型，2=重型，3=混合 CeilingAbs = 天花板声学处理类型：1=多孔类（矿棉），2=其他类（通常为穿孔板材） wallAbs = 墙面吸声材料总面积（单位：m²） --- --- --- 测量得到的室内声学参数按三台麦克风的不同高度分别取房间平均值：低高度（1±0.2 m）、中高度（1.4±0.2 m）及高高度（1.6±0.2 m），并按125 Hz至8000 Hz的倍频程带呈现： XLSX文件"T20"：混响时间T20（单位：s） XLSX文件"EDT"：早期衰变时间（EDT，单位：s） XLSX文件"G"：声强（单位：dB） XLSX文件"C50"：语言清晰度C50（单位：dB） XLSX文件"C35"：积分时长35 ms的语言清晰度C35（单位：dB） --- --- --- 测量得到的空置噪声水平以等效连续声级Leq呈现，存储于电子表格文件"BKG.xlsx"中，覆盖25 Hz至10000 Hz的1/3倍频程带。部分房间还附带了通风系统对背景噪声等效声级的估算贡献值。 XLSX文件"BKG"：等效连续声级（单位：dB） --- --- ---