Design for acoustics

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Specalist terms of modern acoustics

Room acoustics describes the sound situation within specified rooms and is mainly defined by occurring reverb and speech intelligibility. In terms of room acoustics, structural conditions are crucial in the way sound gets in the building from the outside (structure-borne sound).

Reverberation time in rooms defines the period in which a sound event becomes inaudible. This event could colloquially be referred to as an echo. High reverberation time in most rooms leads to poor speech intelligibility.

The frequency (Hertz – Hz) is the number of vibration cycles in seconds caused by a sound event. Short and quick vibrations are responsible for high tones, long and slow vibrations for low tones.

The sound absorption coefficient is a material characteristic that indicates how much sound is absorbed. Ratios are between value 0 (no absorption, i.e. absolute reflection) and value 1 (absolute absorption).

The acoustic properties of a room affect its use. Here, reverberation time again determines whether a room is best used as an office, a classroom, a restaurant, a lecture hall or a concert hall.

What is the role of the ear?

The human ear is the first organ to be formed during the embryonic stage. The reason why we can hear is because of so-called hair cells that grow in the inner ear. Evolutionally, the ear is not only intended for communication – it is also a warning organ. The human hearing ranges from 16 – 20,000 Hz. Infrasound frequencies are below 16 Hz, while the ultrasonic range is above 20,000 Hz, and human speech lies between 300 and 4,000 Hz. The interaction of Hz and dB is of vital importance for hearing, but even more for understanding of sound information in humans.

Noise or harmony

If and when noise becomes a distraction depends, amongst others, on the current situation and on the respective person’s attitude towards that noise. It is not important how loud the noise is. A dripping tap with a sound pressure of less than 20 dB can more likely become a disturbing element than the sound of sea surf at 90 dB. Another paradox of sound is the environment and its speech intelligibility. It is possible to keep up a conversation even in very crowded surroundings like restaurants or bars. This phenomenon has something to do with the human brain, which doesn’t process all noises in a perceptible manner. A person only starts to listen if it understands at least 60% of a spoken word. Good advice means adjusting to a person and its sensory organs. This is our goal.

Rules and DIN standards

According to legal provisions, regulations and DIN standards we make every effort to consider all aspects of human ergonomics. DIN 18041 (audibility in rooms), which came into force in 2016, is the basis for direction and development of the absorbers from Baur. The workplace ordinance §15 is the benchmark for planning and further development to comply with the values required in the premises.

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