Purpose: The aim of this study was to add further knowledge about the usefulness of the Voice Range Profile (VRP) assessment in clinical settings and research by analyzing VRP dual-microphone equipment precision, reliability, and room effect. Method: Test-retest studies were conducted in an anechoic chamber and an office: (a) comparing sound pressure levels (SPLs) from a dual-microphone VRP device, the Voice Profiler, when given the same input repeatedly (test-retest reliability); (b) comparing SPLs from 3 devices when given the same input repeatedly (intervariation); and (c) assessing the room effect. Results: (a) The mean standard deviation across 17 measurement points was 0.7 dB for 1 device. (b) One device was less precise than the other 2 devices. All devices presented high SPLs at low frequencies compared with the reference. (c) Mean SPLs were almost equal in the anechoic chamber and the office. Conclusions: The high test-retest reliability of the dual-microphone VRP equipment, especially in general office surroundings, is a positive finding. Attention must be paid to specific factors such as using the same device when comparing the same voice before and after treatment, caution in headset placement, and manual recalibrations when automatic recalibration occurs. We suggest recalibrations verified with a reference source at regular intervals.