US 8,265,937 B2 · Breathing apparatus speech enhancement using reference sensor

Abstract

Speech enhancement in a breathing apparatus is provided using a primary sensor mounted near a breathing mask user's mouth, at least one reference sensor mounted near a noise source, and a processor that combines the signals from these sensors to produce an output signal with an enhanced speech component. The reference sensor signal may be filtered and the result may be subtracted from the primary sensor signal to produce the output signal with an enhanced speech component. A method for detecting the exclusive presence of a low air alarm noise may be used to determine when to update the filter. A triple filter adaptive noise cancellation method may provide improved performance through reduction of filter maladaptation. The speech enhancement techniques may be employed as part of a communication system or a speech recognition system.

Claims17

Dependent claims

A breathing apparatus speech enhancement system comprising:

a breathing mask;
a primary sensor on the breathing mask and configured to produce a primary signal;
at least one reference sensor on the breathing mask and configured to produce a reference signal;
and,
a processor which combines at least the primary signal and the reference signal to produce an output signal with an enhanced speech component, wherein the processor is configured to:
use a filter to filter the reference signal and subtract the filtered reference signal from the primary signal to produce the output signal;
update the filter based on the output signal and the reference signal;
and
only update the filter when the processor detects the exclusive presence of an alarm signal by:
receiving the primary signal;
determining the energy of the primary signal;
and
analyzing the energy of the primary signal to determine whether the alarm signal is exclusively present.

10 more elements

Dependencies are inferred from the claim text.

Breathing apparatus speech enhancement using reference sensor

Life of this patent

Breathing apparatus speech enhancement using reference sensor

Life of this patent

Abstract

Claims17