Superpositions of delayed and undelayed versions of the same signal can occur at different stages of the audio transmission chain. Often it is a result of multiple microphone signals, sound reflections on walls or latencies in digital signal processing leading to comb-filter-shaped, linear distortions. The measurement of a hearing threshold for this type of distortion with its dependance on reflection delay, relative level and the type of audio content can be the basis for boundaries in everyday recording practice below which undesired timbral distortions can be neglected. Therefore, listening tests were conducted to determine the just noticeable difference for three stimulus categories and different time delays between direct and delayed signal from 0.1 ms to 15 ms, equivalent to 0.03 - 5.15 m of sound path difference, and to reveal the underlying sound qualities. The results show that comb-filter distortions can still be audible if the level of the first reflection is more than 20 dB lower than the level of the direct sound.
https://www.aes.org/e-lib/browse.cfm?elib=14032
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.
Learn more about the AES E-Library
Start a discussion about this paper!
