Figure 5.

A–D, Deletion of M₁, M₃, or M₅ mAChRs did not affect cochlear thresholds (A, B) or suprathreshold responses (C, D), as measured by DPOAEs (A, C) or ABRs (B, D). A, B, Mean DPOAE or ABR thresholds for groups of 6–8 week mutants and wild-type controls (numbers in each group are given in Table 2). C, D, Mean amplitude-versus-level functions for the same animals from A and B, as seen in DPOAEs or ABRs, evoked by tones at 16 kHz (for DPOAEs, f₂ = 16 kHz). For ABRs, only wave 1, the earliest negative–positive deflection, was measured. Error bars in all panels represent SEMs: the symbol key in A applies to all panels.