How to improve speech intelligibility in a bad sound situation without spending any more money.

You've just finished building your nice meeting room. After you try you realize that the meeting room has a bad acoustic sound but you do not want to spend more money.

What should you do?

You can try Lombard Speech. Lombard Speech is the speaking technic that produces better intelligibility speech than normal speech. The differences between Lombard Speech and Normal Speech are:

• increase in phonetic fundamental frequencies

• the shift in energy from low-frequency bands to middle or high bands

• increase in sound intensity

• increase in vowel duration

• spectral tilting

• the shift in formant center frequencies for F1 (mainly) and F2

• the duration of content words are prolonged to a greater degree in noise than function words

• greater lung volumes are used,

• it is accompanied by larger facial movements, though these do not aid as much as sound changes

Lombard's speech technic was developed from the Lombard reflex. The Lombard reflex or Lombard effect was discovered in 1909 by Etienne Lombard, a French otolaryngologist. Lombard effect is the involuntary tendency of speakers to increase their vocal effort when speaking in loud noise to enhance the audibility of their voice. This change includes not only loudness but also other acoustic features such as pitch, rate, and duration of syllables. This compensation effect maintains the auditory signal-to-noise ratio of the speaker's spoken words.

The human brain automatically changes speech made in the noisy space through a process called the Lombard Effect. This happens because humans want to hear their own speech with their ears. Such speech has increased intelligibility compared to normal speech. It is not only louder but the frequencies of its phonetic fundamental are increased and the duration of its vowels are prolonged. People also tend to make more noticeable facial movements.

According to the researchers below listeners hear a Lombard Speech recorded with background noise better than they hear a Normal Speech which has been recorded in quiet with masking noise applied afterward.

Junqua JC on his publication tittle “The Lombard reflex and its role on human listener and automatic speech recognizer” in January 1993, and Summers WV, Pisoni DB, Bernacki RH, Pedlow RI, Stokes MA (September 1988). “Effect of noise on speech production: acoustic and perceptual analyses” in September 1988.

In a typical office, people usually have to raise their voices when they speak in bad sound situations. This is because of the bad acoustic design in your room.

With our experience and expertise, we will be able to help you create an amazing sound in your space. No matter if it's just one classroom or entire university campus! Our services include acoustic measurement & problem analysis, acoustic modeling, recommendation design, hand-over testing commissioning and occupants pre & post-construction satisfaction survey! You can contact us by clicking the contact us button above, so we can discuss how much money you could save by using our services instead of asking multiple contractors separately!