Weissgerber Tobias, Rader Tobias, Baumann Uwe
Audiological Acoustics, ENT Department, University Hospital Frankfurt, Frankfurt am Main, Germany.
Otol Neurotol. 2017 Dec;38(10):e551-e557. doi: 10.1097/MAO.0000000000001524.
To measure speech reception thresholds (SRTs) in co-located (S0N0) and diffuse noise conditions (multi-source noise field, MSNF) and to assess the impact of beamforming algorithms in MSNF in cochlear implant (CI) users.
Non-randomized, open, prospective study.
Tertiary referral cochlear implantation center.
Participants included 14 CI users (7 bimodal, 7 bilateral) and 14 normal hearing young adults.
Cochlear implantation.
SRTs were assessed by means of a German matrix sentence test in either continuous or modulated noise. Loudspeakers were configured in two different conditions: S0N0 and MSNF (speech source in front, four speakers distributed at ±28.6 and ±151.4 degrees). In MSNF, the CI speech processor microphone was set in different directional sensitivity settings: standard (sub-cardioid), fixed (super-cardioid), and adaptive.
In continuous noise, SRTs of both CI groups were comparable. In modulated noise, bimodal CI users showed lower SRTs than bilateral CI group, but significant benefit from glimpsing was only demonstrated in normal hearing participants. All subject groups showed significant spatial release from masking (i.e., SRT improvement in MSNF compared with S0N0 condition) in continuous noise. A tendency of improved SRT (1 dB bimodal, 2 dB bilateral) with fixed and adaptive directional sensitivity was found which could not be statistically confirmed due to large between-subject variations.
The absence of the glimpsing effect in CI users was reaffirmed in the present study. Although very effective in single noise source conditions, the beneficial impact of beamforming algorithms in multiple noise source conditions is poor.
测量在同置（S0N0）和扩散噪声条件（多源噪声场，MSNF）下的言语接受阈值（SRT），并评估波束形成算法在多源噪声场中对人工耳蜗（CI）使用者的影响。
非随机、开放、前瞻性研究。
三级转诊人工耳蜗植入中心。
参与者包括14名人工耳蜗使用者（7名双模使用者，7名双侧使用者）和14名听力正常的年轻成年人。
人工耳蜗植入。
通过德语矩阵句子测试在连续或调制噪声中评估SRT。扬声器配置为两种不同条件：S0N0和MSNF（语音源在前方，四个扬声器分布在±28.6度和±151.4度）。在多源噪声场中，人工耳蜗言语处理器麦克风设置为不同的方向灵敏度设置：标准（亚心形）、固定（超心形）和自适应。
在连续噪声中，两组人工耳蜗使用者的SRT相当。在调制噪声中，双模人工耳蜗使用者的SRT低于双侧人工耳蜗组，但只有听力正常的参与者通过瞥见表现出显著益处。所有受试者组在连续噪声中均表现出显著的空间掩蔽释放（即，与S0N0条件相比，多源噪声场中的SRT改善）。发现固定和自适应方向灵敏度有改善SRT的趋势（双模使用者改善1 dB，双侧使用者改善2 dB），但由于受试者间差异较大，无法进行统计学确认。
本研究再次证实人工耳蜗使用者不存在瞥见效应。尽管波束形成算法在单噪声源条件下非常有效，但在多噪声源条件下的有益影响较差。
