Inventors:
Melvin Duane Frerking - Norcross GA, US
George O'Quinn Hirvela - Carrollton GA, US
Philip R. Specht - Roswell GA, US
Assignee:
AT&T Mobility II LLC - Atlanta GA
International Classification:
H04R 25/00
Abstract:
An apparatus and method for active cancellation of interference at a hearing assistive devices are presented. The apparatus includes an interference cancellation circuit for cancelling an interference component of a composite signal, and an activator circuit for enabling interference cancellation circuit. The interference cancellation circuit generates an estimated replica of the interference from an interference profile, inverts the replica to form a cancellation waveform, then adds the cancellation waveform to the composite signal to cancel the interference component. An interference profile can be provided by performing a training sequence on a composite signal to detect a repetitive signal and building a profile using its parameters, retrieving a profile stored in memory, or using an antenna to capture an RF signal. The activator circuit may enable the interference cancellation circuit when RF energy is detected, when composite signal characteristics match one or more stored profiles, or in response to user input.