Acoustics for Office Spaces

Office Acoustics

Office acoustics plays a major role in the office space environment. Meeting rooms, Video Conferencing rooms and boardrooms require a high level of speech privacy and speech clarity. This means insulating noise from outside from disturbing these spaces. Sound insulation is measured by the transmission loss of partitions. Transmission loss  is a measure of the difference in noise levels between the source room and the receiving room. There are many single number ratings for transmission loss such as STC(Sound Transmission Class), Dw etc.


Speech intelligibility and clarity is another aspect to consider when designing office spaces. Speech clarity is dependent on the reflectiveness of rooms or the echo. The parameter that most determines speech clarity is the reverberation time. Reverberation time(RT60) is defined as the time it takes for sound to decay by 60 decibels. The ideal reverberation times for different spaces is provided in the table below.

Location Volume (m^3) Critical Distance Dc Recommended RT60
 Recording Studio < 50 1.5 m 0.3 s
 Classroom < 200 2 m 0.4 – 0.6 s
 Office < 1,000 3.5 m 0.5 – 1.1 s
 Lecture Hall < 5,000 6 m 1.0 – 1.5 s
 Concert Hall, Opera < 20,000 11 m 1.4 – 2.0 s
 Church 2 – 10 s

Speech Transmission Index(STI) is a single number rating that describes the speech clarity in rooms. It ranges between 0 and 1. 1 being excellent speech clarity and 0 being bad speech clarity.

STI CIS Scale.

STI value Quality according to IEC 60268-16 Intelligibility of syllables in % Intelligibility of words in % Intelligibility of sentences in %
0 – 0.3 bad 0 – 34 0 – 67 0 – 89
0.3 – 0.45 poor 34 – 48 67 – 78 89 – 92
0.45 – 0.6 fair 48 – 67 78 – 87 92 – 95
0.6 – 0.75 good 67 – 90 87 – 94 95 – 96
0.75 – 1 excellent 90 – 96 94 – 96 96 – 100

What we offer?

We coordinate with architects and interior designers on the acoustic design of office spaces keeping factors in mind such as speech privacy, speech clarity, background noise levels, material and budget constraints and aesthetic appeal of materials.

We can provide the following services for your office projects:

  1. Noise survey and mapping. This will provide you with an idea of how well the facade and building exterior should perform acoustically to block external noise from nearby traffic or other sources.
  2. Acoustic design criteria
  3. Acoustic design including facade design
  4. Vibration isolation recommendations for HVAC equipment.
  5. HVAC ducting recommendations
  6. Project supervision and site visits to ensure proper installation and compliance to the design.
  7. Final testing and commissioning

About Us

dB Acoustique are  acoustic consultants based in Bangalore. We undertake small and large office acoustics projects from the treatment of individual rooms to the acoustic design of the entire office floor or building.

About Us

dB Acoustique are Acoustic Consultants based in Bangalore. We offer home, office, room, building, architectural and environmental acoustics and vibration consulting services all over India.

Contact Us


dB Acoustique

Acoustic Consultants



Ph:+91 9448927439