Last Night's TV - The Silence, BBC1; Rich Hall's The Dirty South, BBC4

It happens again and again on television, that what once looked risky and bold winds up looking cynical and tired. Big Brother limps miserably to mind, and any number of panel shows, and now also the scheduling tactic, devalued by its regularity, of "stripping" a drama across the primetime schedules over four or even five successive nights. Look here, the schedulers seem to be saying, we take drama so seriously that we're giving you a whole series in a week.

If it's to work, though, the drama in question needs to be rivetingly good, gathering rather than shedding viewers as the week passes. The opening episode of The Silence, the latest to get this treatment, was watchable enough but fell a little way short of riveting, largely on account of its dispiritingly familiar terrain. That might seem like a harsh assessment of a drama in which the principal character, 18-year-old Amelia (and the hugely promising young actress who plays her, Genevieve Barr), is profoundly deaf, but all around her the clichés pile up like scripts on the floor of a commissioning editor's office.

After all, the drama that revolves around someone out of the ordinary or in some way disadvantaged witnessing a murder is practically a genre in itself. In Rear Window it was a guy in a wheelchair, in Witness it was an Amish child, in Some Like It Hot it was a pair of musicians who quickly discovered a talent for cross-dressing. Here, it's Amelia, who sees a policewoman being deliberately run over, but initially keeps her intelligence to herself, even though she is staying with her uncle, who, yes, happens to be the policeman (Douglas Henshall) in charge of the investigation.

Also undermining the originality of the piece is the casting. Henshall is a marvellous actor, but it's less than a year since we saw him in ITV1's excellent Collision, playing a hard-working detective inspector (a Scot, in an English force) with a daughter in a wheelchair, and here he is as a hard-working detective inspector (a Scot, in an English force) with a deaf niece. Someone could at least relocate him to Clydeside and make him a chief super with no vulnerable female relatives. Still, all credit to them for casting Hugh Bonneville as his equally Glaswegian brother, Chris; a little like casting Stephen Fry as a scouser, and anything but obvious. Less interestingly, Chris's wife, Amelia's over-protective mother, is played by Gina McKee, an actress who specialises in balancing the cares of the world on her pretty shoulders. She could make the choice between double Gloucester and red Leicester look agonising.

Anyway, for all its deficiencies, The Silence has enough going for it to sustain the interest of those of us who invested our time in episode one. Fiona Seres has written a decent script, and director Dearbhla Walsh cleverly evokes the world of deafness. So cleverly, in fact, that the murder narrative seems to me rather less interesting than the story of Amelia and her struggle to come to terms with a new cochlear implant, compounded by the usual teenage challenges of anxious mothers and burgeoning sexuality. It's a shame that such intriguing material should be overwhelmed by all the usual debris of the standard police procedural: the corpses and cordons and, of course, the detective and his long-suffering wife being woken in the dead of night by the ringing phone, without which all such dramas are as incomplete as Columbo sans raincoat.

Someone should set the comedian Rich Hall to work on sending up the worn clichés of the police procedural, because he did a lovely job on the way the cinema in particular has peddled stock images of his native American South. Rich Hall's The Dirty South was a delicious treat, rather like, if he will forgive me, a cold mint julep on a baking Louisiana verandah.

There is, Hall pointed out in his engagingly sardonic, shouty, polemical way, one single defining feature in all films about the South. Just consider the titles: In the Heat of the Night, The Long Hot Summer, and "what was Body Heat but a remake of Double Indemnity with sweat?" But apart from the sizzling sun, he added, the popular view of the South is dominated by the three Rs: rednecks, racism and religion. He went to town (regrettably not in a beaten ol' pick-up truck) on all three, and also asked what other culture would allow its "inherent stupidity" to be mined for comic value? Doing the mining, however, were mostly Hollywood producers and northern publishers. The cartoon strip Li'l Abner, so popular that by 1934 it was syndicated across 900 newspapers and read by 90 million people, was produced by Al Capp from Connecticut, who had spent all of two weeks below the Mason-Dixon line.

Maybe it's because, unlike Al Capp, I once spent a year living in the Deep South that I enjoyed all this more than anything I've watched for ages. Certainly, I could relate to Hall's observation that "it's almost 150 years since the South lost the Civil War... you'd think they'd be over it by now". I, too, can testify that they ain't. But you needed no personal experience of fried chicken and grits to enjoy a script that was frequently laugh-out-loud funny. "Elvis Presley, Johnny Cash, Jerry Lee Lewis and Carl Perkins in the same picture," mused Hall, looking at the famous photograph taken at Sun Studio in Memphis. "If you were a religious scholar, that would be the equivalent of Jesus, Buddha, Mohammed and Carl Perkins in the same picture." Mighty fine stuff.