The level of Maximum Power Output (MPO) of a hearing device plays an important role in a patient’s ability to hear well, especially in noisy situations. As such, it is one of the properties that should be considered by clinicians when choosing a sound processor.
This document discusses the MPO performance of the Cochlear™ Baha® 5 Power, Cochlear Baha 5 SuperPower and the Oticon Medical Ponto 3 SuperPower. It explains the background of the MPO levels presented in the Baha datasheets to demonstrate that they are equivalent to what can be expected to be delivered to the patient. It goes on to demonstrate that the MPO levels presented in the Ponto 3 SuperPower datasheet are higher than what can be expected to be delivered to the patient. This discrepancy is confirmed by data available on the Oticon Medical Genie Medical Software version 2016.1 and also supported by measurements of the Ponto 3 SuperPower.
Extensive measurements confirm that the Baha 5 Power and SuperPower datasheets are accurate representations of the patient available MPO if the gain and MPO levels are set to maximum in the Baha Fitting Software. MPO levels at discrete frequencies for Baha 5 Power and SuperPower taken from their respective datasheets 1,2 are seen in figure 2. When measuring individual devices, slight variations in output may occur due to variations between devices and test systems.
MPO in the Ponto 3 SuperPower datasheet
In contrast to the Baha datasheets, the MPO shown in the Ponto 3 SuperPower datasheet cannot be reached unless a programming interface in combination with a 675P (high power) battery is used as the power supply.3 Additionally the “Full on Gain” setting under the “Technical Measurements” tool available in Genie Medical version 2016.1 needs to be selected. Actual patient available MPO can be visualized when selecting “User setting” in the same tool or through the ordinary fitting tool.
“User setting” and “Full on Gain” curves taken from Genie Medical are seen in figure 4. “User setting” MPO values at discrete frequencies are shown in figure 5.
Discussion and comparison
In many clinics, equipment to verify sound processor performance is not available and datasheets are used to compare different sound processors without measuring them. As earlier described, the MPO stated in the datasheets for the Baha 5 Power and Baha 5 SuperPower can be achieved in a patient fitting. The MPO stated in the Ponto 3 SuperPower datasheet cannot be achieved in a patient fitting. Therefore, to do a true comparison Ponto 3 SuperPower “User settings” data must be used when comparing what MPO the sound processors can deliver to the patient.4 As is seen in the combined data in figure 6, Baha 5 SuperPower has a significantly higher average patient available MPO than both the Baha 5 Power and Ponto 3 SuperPower. The Ponto 3 SuperPower has an average patient available MPO similar to Baha 5 Power.
To validate the comparison presented above, we conducted measurements on the Ponto 3 SuperPower, setting the device to patient available MPO (“User settings”).3 We also measured the Baha 5 Power and SuperPower in the same test set-up. The devices were measured on a skull simulator (TU 1000) at a sound pressure level of 90 dB, with all advanced signal processing features deactivated. They were powered by the company recommended batteries (Ponto 3 SuperPower – 675P high power; Baha 5 Power – 675, Baha 5 SuperPower – rechargeable li-ion). The results as seen in figure 7 reinforce the data in figure 6.