** Bernstein upgrades its rating on Swiss hearing aids maker Sonova SOON.S to "outperform" from "market-perform"
** The broker says the 18% decline in the share price since May is inconsistent with the recent improvement in fundamental drivers
** Stock up 2.3% at 0733 GMT
** The broker notes the U.S. hearing aid market has returned to low single-digit growth in Q2, after a mid-single-digit decline in Q1
** Germany and France also had stronger market unit growth in Q2, Bernstein adds
** A improving underlying hearing aid market, better than expected pricing at U.S. Department of Veteran Affair's and a return to Costco are tailwinds, which should more than offset the additional headwinds from FX, the broker says
(Reporting by Amir Orusov)
((Amir.orusov@thomsonreuters.com))