CORE METHODOLOGY OF IEM TESTING Aim of this methodology is to deliver simple comparison rate for the most people without diving into the complex graphs and diagrams. Take a note that your experience may vary since you have differently shaped ears and not the same hearing spectrum! But despite all appointed facts this review could still be helpful by highlighting hidden things not visible to the online customer. Listener: human being Age: 45 years old Frequency range: 22Hz - 15kHz Audio source: Lotoo PAW Touch GT2 (firmware v1.