Volume control for audio signals

Abstract

A motion picture soundtrack reproduction system has a center front soundtrack channel and a plurality of other soundtrack channels. A volume control adjusts the gain of all the channels. The volume control has a range of settings from a minimum to a maximum, the gain of the center front channel having substantially a first relationship to the volume control settings and the gain of the other channels having substantially a second relationship to the volume control settings, the relationships being such that for a range of volume control settings less than a first setting the gain of the center front channel remains substantially constant while the gain of the other channels decreases as the setting decreases or decreases more gradually than the gain of the other channels as the setting decreases.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS; BENEFIT CLAIM[0001]More than one Reissue Application has been filed for the reissue of U.S. Pat. No. 7,251,337, issued Jul. 31, 2007. The reissue applications are application Ser. No. 12 / 493,111 filed Jun. 26, 2009, Ser. No. 13 / 341,871 filed Dec. 30, 2011, Ser. No. 13 / 341,870 filed Dec. 30, 2011, Ser. No. 13 / 341,873 filed Dec. 30, 2011, and Ser. No. 13 / 341,861 filed Dec. 30, 2011 (the present application). The present application claims the benefit as a Reissue Continuation Application of application Ser. No. 12 / 493,111, filed Jun. 26, 2009 (now RE43,132, issued on Jan. 24, 2012), which is a Reissue Application of U.S. Pat. No. 7,251,337, issued Jul. 31, 2007 (application Ser. No. 10 / 423,829, filed Apr. 24, 2003), the entire contents of all of the foregoing are hereby incorporated by reference as if fully set forth herein, under 35 U.S.C. §120. Applicants hereby rescind any disclaimer of claim scope in the parent application(s) or the prosecu...

AI Technical Summary

Benefits of technology

The invention aims to reduce the loudness of a playback system while maintaining the acoustic level of the center front containing dialogue. This is achieved by designing and installing the cinema equipment in a conventional manner, with a volume control at its standard setting. The reproduced soundtrack channels have a respective gain that produces a respective standard acoustic level in response to a signal having a respective standard reference level in the channel. However, if the volume control is turned down below the standard setting in response to actual or expected complaints from the audience, over a limited range of settings all channels except the center front are attenuated equally. This results in a reduction in overall loudness and an increase in the proportionate contribution of the center front channel, with a potential improvement in intelligibility when the other channels are loud. The balance of the center front to other channels can be adjusted to achieve the desired effect.

Problems solved by technology

Some cinemas have their volume control permanently turned down to such settings because projectionists operating multiplexes with many screens showing different movies simultaneously don't have the time or cannot be bothered to set the controls differently for different movies.

A feature film played with a loudness 6 dB below the calibrated level may have serious dialogue intelligibility problems and very quiet sounds may become inaudible.

In addition, it is possible that the increased use of headroom from Dolby A-type to Dolby SR and digital releases has not been matched by a corresponding increase in power amplifier and loudspeaker capability.

The resultant distortion from overloaded equipment may well exacerbate the loudness problems of recent soundtracks, causing increased incidence of complaints.

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