CPC H04R 29/00 (2013.01) [G01H 3/14 (2013.01); H04R 3/007 (2013.01); H04R 29/008 (2013.01); H04R 2460/15 (2013.01)] | 18 Claims |
1. An earphone comprising:
an Ambient Sound Microphone (ASM), wherein the ASM measures an ambient acoustic environment and generates an ASM signal;
an Ear Canal Microphone (ECM), wherein the ECM measures a second acoustic environment and generates an ECM signal, where the ASM is located further from a user's ear than the ECM when the earphone is inserted into a user's ear;
a speaker;
a memory; and
a logic circuit that performs operations, the operations comprising:
sending a signal output to the speaker;
receiving the ECM signal;
receiving the ASM signal;
calculating a sound pressure level (SPL) using at least one of the ECM signal, the ASM signal or a combination thereof; and
reducing a level of the signal output when the SPL exceeds a threshold value.
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