The detection of hydrogen content in bulk media is a challenging task. Several techniques aiming at measuring the amount of hydrogen require disruption or erosion of the sample. A suite of non-invasive techniques as broad as possible is often needed for bulk samples, and applications to cultural heritage. Electron-Volt neutron spectroscopy is a non-destructive technique for direct counting of hydrogen atoms owing to its mass-resolved nature. Recent experiments on the VESUVIO spectrometer showed the possibility to improve the count rate by modifying the detection procedure, namely lowering the energy threshold for detection of photons on the forward scattering detectors. Our aim is to optimise the hydrogen sensitivity by changing such threshold, and define a new limit of detection.