Chapter 3 — Speech audiometry
SRT, WRS, speech-in-noise, articulation index.
The audiogram of Chapter 2 measures sensitivity to pure tones. But patients live in a world of speech. A patient with an audiogram-derived “moderate” loss may understand conversation comfortably in quiet but become lost in a restaurant. Two patients with identical audiograms may have wildly different real-world function. Speech audiometry — testing the patient’s recognition of actual words and sentences — bridges the gap between the pure-tone audiogram and functional hearing.
Three lessons:
- 3.1 Speech reception threshold and word recognition — SRT, WRS, the psychometric function, rollover as a retrocochlear flag.
- 3.2 The speech banana and the audibility map — the long-term average speech spectrum, phoneme placement, which sounds get lost first.
- 3.3 Speech in noise: HINT, QuickSIN, AI / SII — the SNR loss, modern speech-in-noise tests, the articulation index and its successor the speech intelligibility index.