Prior art

Here is an analysis of the most relevant patent citations for US patent 8582789, based on a review of its cited references and the earliest priority date of April 15, 2003. The selected prior art documents were published before this priority date and cover key aspects of hearing enhancement technology.

Most Relevant Prior Art for US Patent 8582789

1. US5544256A: Hearing aid with adaptive directional microphone

• Full Citation: US5544256A, Killion et al., "Hearing aid with adaptive directional microphone", Issued: August 6, 1996.
• Publication/Filing Date: Issued August 6, 1996; Filed February 27, 1995.
• Brief Description: This patent describes a hearing aid system that incorporates an adaptive directional microphone, often utilizing multiple microphone elements. The primary purpose of this directional microphone is to enhance the signal-to-noise ratio by selectively emphasizing sounds originating from a specific direction (e.g., in front of the user) while attenuating sounds from other directions. This improves the clarity of desired sounds for the hearing aid wearer.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 20: This patent potentially anticipates the general concept of using a microphone with directional capabilities within a hearing enhancement apparatus, as mentioned in Claim 20 ("an interface unit that has... a microphone"). While Claim 20 further specifies a directional speaker and ultrasonic transformation, the use of a directional microphone to improve sound input for hearing enhancement is a fundamental concept disclosed by US5544256A. It also lays groundwork for modifying audio signals based on directional input to enhance hearing.

2. US5682436A: Digital hearing aid and method of digitally enhancing sound

• Full Citation: US5682436A, El-Mallawany, "Digital hearing aid and method of digitally enhancing sound", Issued: October 28, 1997.
• Publication/Filing Date: Issued October 28, 1997; Filed May 2, 1996.
• Brief Description: This patent discloses a digital hearing aid system that employs digital signal processing (DSP) techniques to enhance received audio signals. The system is configured to compensate for a user's specific hearing loss by digitally modifying the sound, often through frequency-dependent amplification or filtering, to provide a personalized hearing experience.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1 & 13: This patent directly anticipates the core functionality of "modifying the down-converted signals into modified signals based on at least one hearing characteristic of the user to enhance the hearing of the user" as recited in Claim 1 and Claim 13. It describes a digital system capable of tailoring sound enhancement to an individual's hearing profile. While it doesn't explicitly describe wireless up-conversion and down-conversion via WiFi, it clearly teaches the "modifier" aspect and the generation of enhanced audio output signals based on user-specific hearing needs.
  • Claim 20: It could potentially anticipate the "at least a portion of the output audio signals have higher power with respect to the received audio signals at corresponding frequencies to enhance the hearing of the user" aspect through its digital sound enhancement capabilities, particularly frequency-dependent amplification. However, it lacks the specific directional speaker and ultrasonic transformation elements of Claim 20.

3. US6466663B1: Digital hearing aid with reduced latency of direct sound

• Full Citation: US6466663B1, Harms, "Digital hearing aid with reduced latency of direct sound", Issued: October 15, 2002.
• Publication/Filing Date: Issued October 15, 2002; Filed August 2, 2000.
• Brief Description: This patent addresses the challenge of latency in digital hearing aids, focusing on minimizing the delay between the direct sound reaching the wearer's ear and the processed, amplified sound delivered by the hearing aid. Reducing this latency helps prevent distracting echo effects and provides a more natural listening experience for the user. It also involves digital signal processing for general sound enhancement.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1 & 13: This patent contributes to the anticipation of the "modifier configured to modify the down-converted signals into modified signals based on at least one hearing characteristic of the user to enhance the hearing of the user." Its focus on reduced latency demonstrates advanced digital signal processing techniques for hearing improvement, aligning with sophisticated "modification" of audio signals. However, the wireless transmission aspects of Claim 1 and 13 are not explicitly disclosed.
  • Claim 20: The patent's emphasis on managing latency for a natural listening experience is relevant to the general operation of a hearing enhancement system, especially one like that in Claim 20 where the ear canal remains open, allowing both direct and enhanced sound to be perceived. This supports the need for rapid "signal processing speed" to prevent echoing, as discussed in US8582789.

These cited patents establish a strong foundation in digital hearing aid technology, including directional microphone concepts and personalized sound enhancement, prior to the priority date of US8582789. However, none of these specific prior art patents explicitly combine all the elements of US8582789's independent claims, particularly the wireless up-conversion/down-conversion via technologies like WiFi (Claims 1 & 13) or the use of a directional speaker transmitting ultrasonic signals that are transformed into audio in air (Claim 20).