Pole-Zero Fitting for Transfer Function of Hearing-Aid Receiver: Evidence-Based Review.

Area of Science:

• Acoustics
• Hearing Science
• Electrical Engineering

Background:

• Balanced Armature Receivers (BARs) are essential hearing-aid transducers, known for high output and frequency response.
• Existing electro-mechanical studies on BARs are limited, necessitating advanced analysis.
• This study is motivated by Hunt's parameter calibration for commercial hearing-aid receivers.

Purpose of the Study:

• To calculate the transfer function (pressure over voltage) of the BAR system from electrical terminals.
• To analyze and validate the transfer function using pole-zero fitting methods.
• To provide an evidence-based understanding of the BAR system's characteristics.

Main Methods:

• Calculated the BAR system's transfer function using Hunt's parameters (1954).
• Employed pole-zero fitting methods (Gustavsen and Semlyen, 1999; Prony, 1975) for analysis.
• Decomposed the transfer function into all-pass and minimum-phase components.

Main Results:

• The transfer function was successfully computed from electrical terminals.
• Gustavsen and Semlyen's method provided a better fit compared to Prony's method.
• The BAR system was confirmed to be a linear, time-invariant, stable, and causal delay system.

Conclusions:

• The study provides a rigorous, evidence-based characterization of the balanced armature receiver.
• Advanced analysis confirms the fundamental properties of the BAR system.
• This research contributes to a deeper understanding of hearing-aid transducer technology.