Microphone combinations of the kind comprising a plurality of directional sound units

• US 3,403,223 A
• Filed: 05/18/1965
• Issued: 09/24/1968
• Est. Priority Date: 05/20/1964
• Status: Expired due to Term

• Current Assignee: Derk Kleis, Hermanus Iding Wilhelmus
• Original Assignee: Derk Kleis, Hermanus Iding Wilhelmus
• Inventors: DERK KLEIS, HERMANUS IDING WILHELMUS
• Application Number:
  US04/456,768
• Time in Patent Office: 1,225 Days
• US Class Current: 381/98
• CPC Class Codes: H04R 1/40 by combining a number of identical transducers specially adapted for hearing aids H04R25/405
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407

Claims