Fig. 1. Schematic diagram of the optical fiber microphone sensing system structure

Fig. 2. Frequency domain output results of the optical fiber microphone sensing system in 0.02-20.00 kHz (inset shows frequency domain output at 0.02 kHz)

Fig. 3. Experimental results of short speech signal detection. (a) Female voice “Help” output result; (b) male voice “Help” output result; (c) short time Fourier transform of female voice “Help” output result; (d) short time Fourier transform of male voice “Help” output result

Fig. 4. Experimental results of long speech signal detection. (a) Optical fiber microphone output result; (b) reference B&K microphone output result; (c) short time Fourier transform analysis of the output results of optical fiber microphone

Fig. 5. System stability test results. （a） Output speech signal after the initial cavity length drift of the sensor； （b） output speech signal after input power attenuation

Fig. 6. DTW analysis results. (a) DTW value of the output speech signal and the initial cavity length drift of the sensor when not affected by the environment; (b) DTW value of the output speech signal after input power attenuation when not affected by the environment