Remote audio recording system



The HARK Receiver


A visitor at a museum with HARK
Remote Audio Recording System for Internet Kiosks (Eavesdropper)


Since the inception of the Minimally Invasive Education (MIE) kiosks, we have been deploying various tools to monitor the unattended devices in these kiosks and the environmental conditions around them from a remote location. But we could not figure out what the users say and feel about the kiosk. CRCS built the Remote Audio Recording System or Eavesdropper, as it’s called, to record and hear kiosk users’ speech and, subsequently, analyze the usage of the MIE kiosk based on what is heard. To carry out the analysis, the recorded speech can be used in conjunction with outputs from other monitoring tools or in isolation. The whole process of recording of the kiosk users’ speech is carried out without the requirement of a field researcher. Eavesdropper is currently being successfully used on one computer at the Madangir Kiosk.

The Remote Audio Recording System or the Eavesdropper is an application that resides on the kiosk computer and uses its multimedia capabilities to capture audio remotely. It records the sounds around the kiosk at pre-defined intervals everyday in the form of audio files. As the raw audio, even of low quality and low sampling rate, is quite bulky making it unsuitable for transfer from the kiosk, these audio files are compressed to MP3 format and then sent over email.

Even after compressing the audio to MP3 format, the size of a 15-minute chunk is somewhere between 850 KB to 2.5 MB. This range is still too big for immediate transmission to CRCS servers. Therefore, we developed two versions of Eavesdropper - one to provide on-demand audio samples of very short duration, and the other to provide audio samples of bigger duration via email. The On-Demand version of Eavesdropper is basically used for monitoring purposes where as the other version is used for analyzing the usage of the MIE kiosks. In terms of the internal working, both the versions function in a similar manner.

Eavesdropper is a fairly rugged application with extensive error handling and diagnostics. It has the following interesting features.
  • Remote Configuration: Eavesdropper is a highly configurable software and the settings used by Eavesdropper are part of a configuration file. This file has values for the timings of each recordings, the length of each recording, the email address to mail MP3 files to, etc. These values can be modified by making available the configuration file with new values at a pre-designated CRCS server. Eavesdropper automatically connects to this server in CRCS and downloads the new configuration settings. In this way, all the Eavesdropper’s settings can be remotely modified.

  • Self-Upgrading: Eavesdropper can upgrade itself, i.e., it can replace its existing version with the latest version. This is similar to the way in which Eavesdropper is remotely configured. The application connects to the CRCS server and downloads it newer version and replaces it self with it.

  • At this point in time, the MIE kiosks do not provide keyboard as an input device. To ensure that kiosk users cannot, accidentally or otherwise, interact with the application, Eavesdropper’s user interface is entirely keyboard-based.


This project reflects the efforts of CRCS in the area of Remote monitoring.


For more details contact: Himanshu Tayal