AES Journal Forum

Why Are Commercials so Loud? ' Perception and Modeling of the Loudness of Amplitude-Compressed Speech*

Document Thumbnail

The level of broadcast sound is usually limited to prevent overmodulation of the transmitted signal. To increase the loudness of broadcast sounds, especially commercials, fastacting amplitude compression is often applied. This allows the root-mean-square (rms) level of the sounds to be increased without exceeding the maximum permissible peak level. In addition, even for a fixed rms level, compression may have an effect on loudness. To assess whether this was the case, we obtained loudness matches between uncompressed speech (short phrases) and speech that was subjected to varying degrees of four-band compression. All rms levels were calculated off line. We found that the compressed speech had a lower rms level than the uncompressed speech (by up to 3 dB) at the point of equal loudness, which implies that, at equal rms level, compressed speech sounds louder than uncompressed speech. The effect increased as the rms level was increased from 50 to 65 to 80 dB SPL. For the largest amount of compression used here, the compression would allow about a 58% increase in loudness for a fixed peak level (equivalent to a change in level of about 6 dB). With a slight modification, the model of loudness described by Glasberg and Moore [1] was able to account accurately for the results.

JAES Volume 51 Issue 12 pp. 1123-1132; December 2003
Publication Date:

Click to purchase paper as a non-member or you can login as an AES member to see more options.

No AES members have commented on this paper yet.

Subscribe to this discussion

RSS Feed To be notified of new comments on this paper you can subscribe to this RSS feed. Forum users should login to see additional options.

Start a discussion!

If you would like to start a discussion about this paper and are an AES member then you can login here:

If you are not yet an AES member and have something important to say about this paper then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.

AES - Audio Engineering Society