PP302 - Comparison of Acoustical and Perceptual Outcomes Between the ActiveVent and Standard Receivers

Abstract:
This study investigated the clinical differences between the ActiveVent™ (AV) and standard receivers. Software simulations, real ear measures on Kemar, and objective and subjective measures on participants were completed using five groups of high-frequency sensorineural hearing losses. Results revealed that AVclosed has more gain, maximum gain before feedback, and microphone directionality but relatively less speech enhancer feature than open conditions. Kemar results confirmed the possible energy leaking to/from openings, using speech enhancement features for AVclosed, and change in maximum gain before feedback for each individual. Results from participants are discussed, providing useful information for receiver selection.

Summary:
Venting is important when fitting hearing aids, especially for those with normal to mild hearing loss (HL) at low frequencies. Open fit using large vent sizes or open domes are commonly used to address possible occlusion effect to improve sound quality, but with possible drawbacks of feedback, decreased gain, and reduction of benefits from features such as directional microphones and noise reduction (e.g., Winkler, Latzel, Holube, 2016). Closed fit with no vent will help address issues from open fit, but own voice quality issues remain. Phonak’s ActiveVent™ receiver (AV) can open the vent in quiet environments and automatically switch to a closed fit in noisy environments. However, it is not clear what the fitting outcomes are with this new receiver. This study investigated the acoustical and perceptual differences for listeners with different degrees of HLs between AV and the standard receiver with open domes.

This study included software simulations, real ear measures on Kemar, and objective and subjective measures on participants. All sections were completed using five groups of hearing: normal hearing, mild, moderate, moderately severe, and severe high-frequency sensorineural HLs. Phonak software was used with Audéo P90-R hearing aids. Test conditions included a standard receiver with an open dome and AV with a universal and/or custom slimtip with no vent in quiet and noise (3dB SNR). Gain for different inputs, maximum gain before feedback, and hearing aid features were recorded from the software. Real ear aided gain and output for different inputs were recorded in quiet and noise for different HLs on Kemar and each participant. Each participant also completed a word recognition test in quiet and noise and a questionnaire regarding their sound perception and receiver/earpiece fit for each condition. Data recorded were analyzed using Matlab for multiple comparisons.

Results revealed that the software provides similar gain for open conditions but relatively more gain for AVclosed (within 10dB). There is more maximum gain before feedback for AVclosed across all frequencies, the same gain at 3-8kHz for open conditions, and more gain below 3kHz for AVopen than the standard open. Feature differences are in microphone directionality (AVclosed: StereoZoom; open: 4-real ear sound) and speech enhancer (AVclosed: weak; open: moderate). On Kemar, in quiet, open conditions had significantly lower output (more than 10dB) at 6-8kHz than targets, confirming the possible leaking energy from the opening. In noise, AVclosed had significantly more gain and output (up to 25dB) at mid frequencies, but significantly less gain (up to 24dB) mostly at low frequencies than the standard open. This could be due to noise entering from the opening for the standard open and the speech enhancement features for AVclosed. The maximum gain before feedback increased at 1500-3000Hz for Kemar, indicating the importance of feedback manager for each individual. Among those participants who completed the study, the gain and output had a similar trend to Kemar. Participants with normal hearing had relatively better word recognition in noise with AV and preferred this receiver. One participant with HL had slightly better speech recognition with the standard receiver and no preference between the receivers. Data collection is still ongoing. Information obtained will be useful for receiver selection.