In concert halls, theaters, houses of worship, rehearsal rooms, and other areas where sound quality is critical, masonry is the architect's and his client's best friend. Building in heavy masonry—brick or medium-to-normal weight grout-filled block—is the simplest and most direct path to achieving high quality acoustic performance.

Masonry provides mass, which supports low frequency response. This is the visceral bass fundamental on which all the higher frequencies are based. The building material offers a wide choice of irregular and shaped surfaces—from split-face to wave-shaped—that enhance the scattering of high frequency sound.

Masonry also provides excellent isolation of sound. With sufficient mass and thickness, double-wythe construction (where needed) and acoustic sealing of all junctions and penetrations, masonry is an excellent material for excluding unwanted sound from the exterior or adjacent spaces.

Because masonry construction is built using small units, it can readily be configured to provide proper acoustic shaping—curves, waves, angles, and offsets. This gives the architect greater design flexibility.

It is truly a magnificent material for achieving superlative acoustic performance in buildings.

Acoustic quality

We live in a full-frequency world. Our ears are designed to hear a sound spectrum that we think of as natural, ranging from low bass frequencies to high overtones. We can also perceive a wide dynamic range, from the loudest overwhelming level of an orchestra playing fortissimo to the subtlest high note played pianissimo — or the noise of a leaf-blower versus a whisper.

Therefore, it is critical to design interior spaces to support the full range of frequencies that humans are able to hear. This applies not only to music venues, but also to spaces where speech is important, such as theaters, houses of worship, and educational facilities.

When we are born, our ears typically hear from 20 Hz to 20,000 Hz. This range declines with age, particularly in the high frequencies. It is a rare middle-aged adult who hears up to 16,000 Hz, and a rare older adult who hears at 8000 Hz or above.

The notes on a piano keyboard range from 27 Hz to 4186 Hz. Overtones for the highest notes of the piano extend the range of upper frequencies to above 10,000 Hz. High end audio systems are typically designed for a range from 20 Hz to 20,000 Hz.

It is common for the speech intelligibility range to be defined as 500 Hz to 4000 Hz. However, the actual frequency range of the human voice is much wider. The fundamentals of male voices extend down to the 100 Hz range, while overtones of female voices extend to around 8000 Hz. Vowels and bass notes are in the low frequencies, while consonants and overtones are in the high frequencies.