Acoustics is defined as the science that deals with the production, control, transmission, reception, and effect of the sound [
1]. External ear acoustics is the modulation of sound in the ear canal. The external auditory ear canal transfers soundwaves from the concha to the eardrum and acts as a resonant tube [
2]. Due to its anatomical dimensions the external auditory ear canal acts as a filter to reduce low frequencies and enhance mid to high frequencies [
3]. Surgical modification of the osseous external auditory canal (OEAC) changes the acoustic properties of the external ear canal [
4‐
9]. For example, in case of a cavity condition, the acoustic properties shift towards an amplification of the soundwaves of low to mid frequencies and an reduction in soundwaves of high frequencies [
8]. In case of revision, radical cavity surgery with reconstruction of the posterior wall of the cavity near-normal acoustic characteristics were measured [
9]. Even less extensive surgical alterations of the OEAC, such as an osseous canalplasty, lead to changes in ear canal acoustics [
9]. These observations seem to indicate that volume changes of the ear canal lead to alterations in ear canal acoustics [
8,
9]. In previous studies, we have demonstrated that these surgical alterations of the OEAC provoke an altered perception of the sound [
8,
9]. In patients with hearing loss and hearing aids, we know that altered acoustics result in a reduced quality of life [
10,
11]. For clinicians, it would be very helpful to be able to inform patients pre-operatively to what extend their ear canal acoustics changes after surgery of the ear canal. Therefore, we have to assess to what extent patients are able to recognize differences in ear canal acoustics, by investigating the relation between the objective measurement and subjective experience of the acoustics of an altered ear canal. Although a correlation between subjective sound quality assessment and objective acoustic quality assessment in Portuguese churches has been described earlier [
12], to our knowledge we are the first to investigate the correlation between objective measurements of external auditory canal acoustics and subjective quality assessment of ear canal acoustics.
The primary objective of this study is to correlate subjective quality assessment of acoustics to the objective measurement of external ear canal acoustics. Our second objective is to design a model to predict the subjective quality of sound based on the altered objective ear canal acoustics.