1. Various Technical Topics on the development of ASEP
10 July 2018
P R E S E N T A T I O N O F
INTERNATIONAL ORGANIZATION OF MOTOR VEHICLE MANUFACTURERS
Various Technical Topics on the development of ASEP

2. Acoustic Memory on Perceived Sound and Annoyance Aspects
Perception of Sound
Acoustic Memory on Perceived Sound and Annoyance Aspects

3. Acoustic Memory
Humans have no memory for sound pressure or the subjective perceived sound volume. (
Experiment:
When two sounds which differ by 3 dB are presented with a time delay, it is difficult to decide which sound is louder.
Reference sound Comparative sound Which sound is louder?
1000 Hz Hz
Only without a break one can "hear" which of the two sounds (by 3 dB) is quieter.

4. … it not only a question of sound level
SOUND or NOISE ?
30 dB
100 dB dB
30 dB
… what we
accept or reject …
… it not only a question of sound level dB
100 dB

5. Acoustic Memory SOUND Person individual influence factors
Humans analyse permanent incoming sound for information.
Decision
of Receiver
Signal Analysis
(Cocktailparty Effect)
Pleasure
SOUND
Person individual influence factors
Acceptance
Annoyance
Thus it is difficult to say, weather the perceived information or the sound level of the signal is rated as annoyance or not.

6. Acoustic Memory
Humans have no memory for sound pressure or the subjective perceived sound volume. (
When can humans hear a change in sound level?
Reference Comparative Comparative Comparative
Sound Sound #1 Sound #2 Sound #3
1000 Hz Hz Hz 1000 Hz
A difference of 6 dB is audible and will be recognized by everybody. The capability to hear differences is frequency and sound level dependent.
But… … is 6 dB a difference or a significant difference?