A simple audio data logger for objective assessment of snoring in the home

We have developed a portable device for patient use in logging snoring loudness in the home, for guiding treatment decisions and measuring the clinical effectiveness of treatment. The device uses a free field microphone and is positioned on a bedside table. The prototype devices contain no inherently expensive components and are simple to operate (producing only 5% patient error to date). They are portable, battery powered, rugged and produce digital data which are easily and automatically analysed, and these design parameters enable the devices to be used for first line patient assessment. Of the 75 recordings made so far from 30 patients, 85% were successful, yielding clinically useful data. Because it is sound levels which are recorded and not replayable sounds, patient privacy is maintained, resulting in excellent patient acceptance (to date no patient has refused). The device has a dynamic range of 45-90 dB sound pressure level and a frequency range of 30 Hz-5 kHz. Because snoring intensities often vary significantly throughout the night the device can measure continuously over 8 h.