Acoustic-based temperature sensing in telephones

摘要

A communication device includes a speaker, a microphone, and a processor connected to the speaker and the microphone. The processor is arranged for calculating ambient temperature by playing a test sound on the speaker, measuring a transit time of the test sound from the speaker to the microphone, and determining the ambient temperature from the measured transit time. A method of calculating ambient temperature by using a communications device having a speaker, a microphone and a processor is also disclosed. The method can be used for monitoring ambient temperatures of machinery and for detecting fire conditions.