MULTIPLE SUPERIMPOSED AUDIO FREQUENCY TEST SYSTEM AND SOUND CHAMBER WITH ATTENUATED ECHO PROPERTIES

• US 20120243697A1
• Filed: 05/30/2012
• Published: 09/27/2012
• Est. Priority Date: 02/10/2009
• Status: Active Grant

• Current Assignee: Fry's Electronics, Inc.
• Original Assignee: Fry's Electronics, Inc.
• Inventors: Frye, George J.
• Granted Patent: US 8,995,674 B2
• Time in Patent Office: Days
• US Class Current: 381/58
• CPC Class Codes: H04R 25/30 Monitoring or testing of hearing aids, e.g. functioning, settings, battery power
• CPC Class Codes: H04R 29/00 Monitoring arrangements; Testing arrangements for hearing aids H04R25/30; detection of loudspeaker connection H04R5/04; sound-field adaptation dependent on speaker detection H04S7/308

Abstract

A composite sound dampening structure includes a first base layer of sound dampening material extending around and against an inside surface of a container and a second wedge layer of sound dampening material attached to an inside surface of the first base layer. The composite sound dampening structure provides improved acoustic dampening in relative small sound chambers. An audio test system generates a composite audio signal of multiple different audio signals that are combined together using linear superposition. The composite audio signal allows a device to be simultaneously tested with multiple different audio frequencies.

Claims

1. A sound dampening device, comprising:

a portable container; and

a composite sound dampening structure comprising a first base layer of sound dampening material extending around and against an inside surface of the container and a second wedge layer of sound dampening material attached to an inside surface of the first base layer, the composite sound dampening structure forming an internal cavity inside of the container configured to retain a speaker and audio receiving device.

2. The device according to claim 1 wherein the portable container includes a bottom section that contains a bottom section of the composite sound dampening structure and a detachable separate upper section that contains an upper detachable separate section of the composite sound dampening structure.

3. The device according to claim 1 wherein the first and second layers of the composite sound dampening structure each comprise a foam or fiberglass material.

4. The device according to claim 3 wherein the first layer comprises a felted open cell foam and the second layer comprising a 5 pound carpet foam.

5. The device according to claim 1 wherein the first layer is around 1.5 inches thick and the wedges are around 2.5 inches in height.

6. The device according to claim 5 wherein the container is around 12-15 inches in height and width, and around 16 to 19 inches in depth and the cavity formed in the center of the container by the composite sound dampening structure is around 4 inches in height and width and around 8 inches in depth.

7. The device according to claim 1 further comprising a test system configured to superimpose multiple different acoustic signals having different frequencies together into a single composite signal that is output from the speaker and used for testing directional and frequency characteristics of the audio receiving device contained within the cavity of the container.

8. The device according to claim 7 wherein the test system is further configured to convert a test signal received from the audio receiving device in response to the composite signal into separate frequency and amplitude components corresponding with the different acoustic signals and convert the frequency and amplitude components into polar plots corresponding to the different acoustic signal frequencies.

9. The device according to claim 7 further comprising a support structure including a column that extends up from a bottom floor of the chamber through both the first base layer and second wedge layer and suspends the audio receiving device within the cavity formed in the container, the support structure rotating the device under test into different horizontal and/or a vertical orientations with respect to the speaker.

10. A system for attenuating echo in acoustic waves, comprising:

a first base layer of sound dampening material having a first side for placing against an inside surface of a wall, the first base layer configured to attenuate the acoustic waves;

a separate second sound dampening layer having a first side for attaching to a second side of the first base layer and a second side for initially receiving the acoustic waves,

the second layer configured to attenuate smaller acoustic waves while also reflecting the smaller acoustic waves toward the first base layer for further attenuation,

the second layer further configured to provide reduced reflections and attenuation of larger acoustic waves while the larger acoustic waves move toward the first layer for additional attenuation.

11. The system according to claim 10 further comprising a relatively small portable acoustic test chamber having an inside surface that is substantially covered by the first and second layer.

12. The system according to claim 11 wherein the first and second layer form an inside cavity within the test chamber configured to retain and test directional acoustic characteristics of a microphone or speaker.

13. The system according to claim 11 wherein the first and second layer form an inside cavity within the test chamber configured to retain and test directional acoustic characteristics of hearing aids.

14. The system according to claim 10 wherein the first and second layers comprise different fiberglass and/or foam materials.

15. The system according to claim 14 wherein the first layer comprises substantially rectangular or square pieces of foam and the second layer comprising wedges with a triangular cross-sectional shape.