نوع مقاله : مقاله پژوهشی

نویسندگان

• عباس غفاری ¹
• فرزانه قلیزاده ²

¹ دانشیار، دانشکده معماری و شهرسازی، دانشگاه هنر اسلامی تبریز، تبریز، ایران.

² دانشجوی دکترای معماری اسلامی، دانشکده معماری و شهرسازی، دانشگاه هنر اسلامی تبریز، تبریز، ایران.

چکیده

شنوایی در انسان حسی است که در انتخاب ورودی‌ها نقشی ندارد و ناخود آگاه در برابر صداها قرار می‌گیرد. محیط زندگی انسان، سرشار از این اصوات است و منابع مختلفی به ازدیاد آن کمک می‌نمایند که در هر محیطی بسته به موقعیت انسان، تعریف حداکثری برای میزان بار وارده صوتی به گوش انسان تعریف می‌شود. مساجد به عنوان عملکردی خاص در زمینه آکوستیک نیازمند رفتارهای چندگانه در این حوزه‌اند. مسجد ایده‌آلِ آکوستیکی بایستی بتواند در عین این‌که به فضاهای خلوت و تمرکز فردی اهمیت می‌دهد؛ در پخش مناسب صدا به منظور کاربردهای جمعی نیز موفق عمل نماید. به نظر می‌رسد رفتار کلی صوتی در مساجد با فرم و ساختار سنتی در احجام کمتر همگن‌تر بوده، تراز فشار صدا را در کلیت فضا بالاتر نشان دهد و در نمونه‌های حجیم‌تر مکان‌های متعدد با فشار بالای صدا اما ناهمگن بوجود آید. به منظور واکاوی فرضیه‌ی مذکور، طرح مطالعاتی پیش رو، در دو فاز مطالعاتی و میدانی انجام یافته و تحلیل رفتار صوتی دغدغه اصلی پژوهش است تا بتوان در گونه‌های مختلف حجمی تفاوت ‌های آکوستیکی را با تکیه بر ابزارهای سنجش بروز که ارائه دهنده نتایج کارآمدتری نیز خواهد بود؛ بررسی و تحلیل نمود. نتایج پژوهش نشان می‌دهد افزایش حجم در ساختار یکسان نمونه‌ها، موجب کاهش فشار صدا در بنا می‌شود و در عین حال زمان واخنش افزایش می‌یابد. این مقوله به فرکانس وابستگی مستقیم دارد و در فرکانس‌های پایین‌تر، افزایش حجم تاثیر کمتری در تراز فشار صدای فضا دارد.

تازه های تحقیق

- مطالعه در کنار استفاده از ابزارهای متداول آکوستیک معماری (B&K 2260 Investigator) برای اولین بار در مساجد از تجهیزات بروز (Acoustic Camera) نیز بهره برده است.

- رفتار کلی صوتی در مساجد با احجام کمتر همگن‌تر بوده، تراز فشار صدا در کلیت فضا بالاتر است و در نمونه‌های حجیم‌تر مکان‌های متعدد با تراز فشار بالای صدا اما ناهمگن بوجود می‌آید.

کلیدواژه‌ها

• آکوستیک
• معماری مساجد
• تغییرات حجمی
• رفتار صوتی

عنوان مقاله [English]

Analysis of impact of volume changes on acoustic behavior in mosques (Case study: Historic masques of Tabriz)

نویسندگان [English]

• Abbas Ghaffari ¹
• Farzaneh Gholizadeh ²

¹ Associate professor, Faculty of Architecture and Urbanism, Tabriz Islamic Art University, Tabriz, Iran.

² Ph.D. Candidate in Islamic Architecture, Faculty of Architecture and Urbanism, Tabriz Islamic Art University, Tabriz, Iran.

چکیده [English]

Extended Abstract
Background and Objectives: Hearing in human is a sense which has no role in selection of entries and is unconsciousness exposed to sounds. The environment that human lives in, is overfilled with such sounds and various sources contributes to its increasing so that in every environment, depending on the location of human, maximum definition for the amount of imposed sound load to human ear is determined. Architecture limits and frames sound. This causes the sound to behave differently indoors than outdoors. The type of difference is sometimes desirable and sometimes undesirable, and this is due to different architectures. There are many effective components in the formation of architecture and body of a place, but the first studies in the field of Acoustics in architecture, which has shown with Sabine’s formula, has prioritized the volume, material and surface of space among all the factors that shape the body. As mosques are of a particular function in terms of acoustics, they require multiple behaviors in this field. An acoustically ideal mosque not only should provide quiet spaces and make individual concentration possible but also perform successfully in appropriate distribution of sound regarding collective uses and according to Sabin’s formula, this will be possible due to the volume, material and area of space.
Methods: The present study has tried to keep the parameters affecting the sound measurements constant in order to be able to analyze the effect of volume changes on the acoustic behavior of mosques. It seems that the general sound behavior in mosques with the traditional form and structure is more homogeneous in less volumes, and shows the sound pressure level in the whole space is higher, and in larger samples, several places with high SPL but heterogeneous sound appear. In order to analyze the hypothesis, the present study has been carried out in two phases of theoretic study and field study, and the analysis of acoustic behavior is the main concern of the research to differentiate between acoustics in different volumetric types by using advanced tools that provide efficient Achievements. In order to measure the Reverberation time, the 2260 device of B&K Denmark has been used and several points have been measured in mosques depending on the size of the plan surface. Imaging with a SINUS Acoustic Camera was also performed in two positions. In the first case, the general noise of the samples was recorded and in the second position, the sound source was used. In all the examples, the position of the source in the Mihrab is considered so that it can be used as a simulation of the general state in which the preacher is placed in the Mihrab. The selected frequency range is up to 10 kHz.
Findings: Findings show that with a constant sound distribution of 94 decibels in all samples, the largest volume has the lowest sound pressure level and in proportion to the volume of the rest of the samples have higher values. This shows that with increasing volume, the effect of loud noises in space is much less felt. This acoustic event intensifies with increasing frequency and the effect of volume is less at low frequencies. On the other hand, increasing the volume increases the Reverberation time, and this change, in contrast to the SPL, is greater at lower frequencies. In other words, the volume at lower frequencies is an effective factor in changes in the Reverberation time and does not play a significant role in the Reverberation time of space at high frequencies.
Conclusion: The results show that increasing the volume in the same structure of the samples reduces the sound pressure level in the building and at the same time increases the Reverberation time. This is directly dependent on the frequency, and at lower frequencies, increasing the volume has less effect on the sound pressure level. In Reverberation time factor, the frequency behavior is inverse and the volume will be less effective at higher frequencies, which proves the acoustic balance in the samples. The three factors of volume, Reverberation time and sound pressure level vary in relation to the frequency range and depending on the frequency spectrum vary the volume, Reverberation time and sound pressure level relationships. The usage of this finding will be effective in the design of mosques with a similar structure, because depending on the desired volume, the Reverberation time and the desired sound pressure level can be predicted. On the other hand, since in mosques and any other use, the standard amount is defined for Reverberation time; In order to achieve the expected Reverberation time, the volume of the space can be designed and the sound pressure level can be adjusted.

کلیدواژه‌ها [English]

• Acoustics
• Architecture of Mosques
• Changes in Volumes
• Sound Behavior