Masking for SRT Crosshearing suspected when SRTTE – IA ≥ Best BCNTE In that case, present speech noise to the NTE at a level equal to SRTNTE. If no change in SRTTE , then original SRT was correct. If change, then use plateau method to obtain correct threshold. Record masked SRT in audiogram. 1

Other speech tests Most comfortable level (MCL): Usually around 40-55 dB SL. Instruct patient to indicate if speech is soft, too loud, most comfortable, etc. Repeat several times. Uncomfortable level (UCL): Usually around 100-110 dB HL. Instruct patient to indicate if speech is comfortable, loud, or uncomfortably loud etc. Repeat several times. Dynamic range: UCL-SDT: Usually around 100 dB or more. 2

Speech recognition scores Used to measure recognition of speech when presented at a comfortable level. Most popular materials: Phonetically balanced (PB) word lists: Each phoneme appears with the same frequency it has in the normal lexicon. Example: CID W-22 word lists Phonemically balanced word lists: Takes into account all the variations that a single phoneme can have (allophones). Example: NU-6 word lists (CVC format) Sentence lists: Can be meaningful (CID everyday sentence list), nonsense (Synthetic sentence identification or SSI), presented in quiet or in noise (Speech perception in noise or SPIN). 3

Issues with speech recognition Closed-set versus open set responses Forced versus free response Cross-hearing: Suspected when PBHLTE- IA ≥ Best BCNTE Generalization to everyday situations 4

Performance-intensity function Percentage of correct identification of PB words at various levels. For normal-hearing adults, maximum PB score (100%) is achieved at 35-40 dB above the SRT. Highest PB score: Called PBmax 5

Performance-Intensity functions 6