ECHO, THE LOMBARD EFFECT, AND TIME DELAY
- Humans are used to hearing their voice while they speak - real-time
feedback (side tone).
- When we place headphones over our ears, which dampens this feedback,
we tend to speak louder.
- Lombard Effect: Humans speak louder in the presence of
ambient noise.
- When this side-tone is delayed, it interrupts our cognitive processes,
and degrades our speech.
- This effect begins at delays of approximately 250 ms.
- Modern telephony systems have been designed to maintain delays
lower than this value (long distance phone calls routed over
satellites).
- Digital speech processing systems can introduce large amounts of
delay due to non-real-time processing.