Effects of dynamic range compression on spatial selective auditory attention in normal-hearing listeners

This study investigated the effects of fast-acting hearing-aid compression on normal-hearing and hearing-impaired listeners' spatial perception in a reverberant environment. Three compression schemes—independent compression at each ear, linked compression between the two ears, and “spatially ideal” compression operating solely on the dry source signal—were considered using virtualized speech and noise bursts. Listeners indicated the location and extent of their perceived sound images on the horizontal plane. Linear processing was considered as the reference condition. The results showed that both independent and linked compression resulted in more diffuse and broader sound images as well as internalization and image splits, whereby more image splits were reported for the noise bursts than for speech. Only the spatially ideal compression provided the listeners with a spatial percept similar to that obtained with linear processing. The same general pattern was observed for both listener groups. An analysis of the interaural coherence and direct-to-reverberant ratio suggested that the spatial distortions associated with independent and linked compression resulted from enhanced reverberant energy. Thus, modifications of the relation between the direct and the reverberant sound should be avoided in amplification strategies that attempt to preserve the natural sound scene while restoring loudness cues.

Section: Discussionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Effects of hearing-aid dynamic range compression on spatial perception in a reverberant environment

Hassager

Wiinberg

Dau

2017

“…The digit stimuli used in the digit identification task were the same as used by Schwartz and Shinn-Cunningham (2013). They consisted of the ten digits from "zero" to "nine" spoken by a male talker, recorded in a sound-isolated booth (with carpeted floor and perforated metal walls and ceiling) with an Audio-Technica AT4033 microphone and an Apogee Duet audio interface at a sampling rate of 16 kHz.…”

Section: B Digit Stimulimentioning

confidence: 99%

“…For these reasons, unaided and aided speech perception by HI listeners in multitalker situations with spatially separated target and interfering sources has received much attention (e.g., Bronkhorst and Plomp, 1989;Moore et al, 1992;Noble et al, 1997;Peissig and Kollmeier, 1997;Marrone et al, 2008a,b;Neher et al, 2009;Brimijoin et al, 2012;Schwartz and Shinn-Cunningham, 2013). However, irrespective of whether spatialization in these studies was realized by using loudspeaker arrangements or head-related transfer functions, the simulated acoustic scenarios had one thing in common: All sources were facing the listeners, i.e., they had their "faces" turned toward the listeners and were "gazing" straight at them; see Fig.…”

Section: Introductionmentioning

confidence: 99%

Effects of interferer facing orientation on speech perception by normal-hearing and hearing-impaired listeners

Strelcyk

Pentony

Kalluri

et al. 2014

There exist perceptible differences between sound emanating from a talker who faces and a talker who does not face a listener: Sound from a non-facing talker is attenuated and acquires a spectral tilt. The present study assessed the role that these facing-orientation cues play for speech perception. Digit identification for a frontal target talker in the presence of two spatially separated interfering talkers was measured for 10 normal-hearing (NH) and 11 hearing-impaired (HI) listeners. Overall-level differences and spectral tilts were reproduced by means of digital filtering and playback via loudspeakers. Both NH and HI listeners performed significantly better when the interfering talkers were simulated not to be facing them. Spectral tilts and level differences across talkers reduced target-interferer confusions. They enabled the NH listeners to sequentially stream the digits. This was not the case for the HI listeners, who showed smaller benefits, irrespective of whether they were aided by their own hearing aids or not. While hearing-aid amplification increased audibility, it may not have aided target-interferer segregation or target selection. The present results suggest that facing orientation cannot be neglected in the exploration of speech perception in multitalker situations.

“…This shared processing is commonly referred to as "linked" compression, such that in the case of a symmetrical hearing loss the amplification provided by the two compressors is the same in both ears and, as a consequence, the intrinsic ILDs are preserved. This has been shown to improve the ability of normal-hearing listeners to attend to a desired target in an auditory scene with spatially separated maskers as compared to independent compression in reverberant conditions (Schwartz and Shinn-Cunningham, 2013).…”

mentioning

confidence: 99%

Preserving spatial perception in rooms using direct-sound driven dynamic range compression

Hassager¹,

May²,

Wiinberg³

et al. 2017

Fast-acting hearing-aid compression systems typically distort the auditory cues involved in the spatial perception of sounds in rooms by enhancing low-level reverberant energy portions of the sound relative to the direct sound. The present study investigated the benefit of a direct-sound driven compression system that adaptively selects appropriate time constants to preserve the listener's spatial impression. Specifically, fast-acting compression was maintained for time-frequency units dominated by the direct sound while the processing of the compressor was linearized for time-frequency units dominated by reverberation. This compression scheme was evaluated with normal-hearing listeners who indicated their perceived location and distribution of sound images in the horizontal plane for virtualized speech. The experimental results confirmed that both independent compression at each ear and linked compression across ears resulted in broader, sometimes internalized, sound images as well as image splits. In contrast, the linked direct-sound driven compression system provided the listeners with a spatial perception similar to that obtained with linear processing that served as the reference condition. The independent direct-sound driven compressor created a sense of movement of the sound between the two ears, suggesting that preserving the interaural level differences via linked compression is advantageous with the proposed direct-sound driven compression scheme.